Did you actually read the article you linked? It backs up that dispersal of the square was relatively peaceful. This isn't even getting into conflicting sources, such as leaked cables backing up what I said, your source just doesn't agree with you. Here's what Wikipedia, horribly biased as it is, has to say:

Troops from the west arrived at the square at about 1:30 am, and troops from other directions gradually arrived as well, blocking main roads to the square to prevent entry.[198] A second emergency announcement from the government was broadcast on loudspeakers:

A severe counterrevolutionary riot has broken out in the capital tonight. Rioters have savagely attacked soldiers of the PLA, have stolen their weapons and burned their vehicles, have erected roadblocks, and have kidnapped officers and soldiers [...] Citizens and students must evacuate the Square immediately so that martial law troops can successfully carry out their mission. We cannot guarantee the safety of violators, who will be solely responsible for any consequences.

— Emergency Announcement, Beijing Municipal Government and Martial Law Command[199]

After the announcement, most people in the square began to leave, and by 2:00 am, there were only a few thousand demonstrators in the square.[199] North of the square, a dozen students and citizens attempted to torch army trucks with cans of gasoline but were arrested.[199]

At 3:00 am, Hou Dejian, Liu Xiaobo, Zhou Duo, and Gao Xin decided to convince the students to evacuate the square; Chai Ling, however, insisted that "those who wish to leave may leave, and those who don't may stay."[200] The group asked Chai Ling and other student leaders to negotiate a peaceful evacuation. Hou Dejian addressed the students by loudspeaker, urging them to leave the square and surrender their rifles and other weapons, before leaving with Zhou Duo in an ambulance to meet the government troops.[198][200]

Between 3:30 and 3:45 am, the ambulance arrived at the Museum of Chinese History in the northeast corner of the square, and Hou Dejian and Zhou Duo met with Ji Xinguo, a regimental political commissar.[198][200] They requested that the army give them time to evacuate, and to open a path for them to leave. Ji Xinguo relayed their request to Martial Law Headquarters, who agreed to the students' request.[198][200] Ji Xinguo informed them of this and told them to exit to the south. After Hou and Zhou returned to the square, they called for an immediate evacuation, and the Martial Law Headquarters announced, "Students, we appreciate that you will leave the Square voluntarily. Students, please leave in the southeastern direction."[201]

There was initial reluctance among the students to leave, but as the deadline approached, Feng Congde asked students for a voice vote on whether to stay or leave.[201] Although the vote's results were inconclusive, Feng said the vote to leave was louder.[201] The demonstrators began to evacuate, with students leaving under their school banners, heading southeast.[200][182] At about 4:35 am, a few minutes after the demonstrators started to retreat, the lights in the square were turned on, and troops began to advance. A squad of commandos charged up the monument and shot out the students' loudspeaker.[202][201] According to Hou Dejian, tear gas was used during the operation to clear the square.[203]

At 5:23 am, a Chinese unit crushed the Goddess of Democracy statue, removing its severed torch first as a memento.[204]

Having removed the students from the square, soldiers were ordered to relinquish their ammunition, after which they were allowed a short reprieve, from 7 am to 9 am.[205] The debris left over from the student occupation was either piled and burnt on the square or placed in large plastic bags that were then airlifted away by military helicopters.[206][207] After the cleanup, the troops stationed at The Great Hall of the People remained confined within for the next nine days. During this time, the soldiers were apparently left to sleep on the floors and were daily supplied a single packet of instant noodles shared between three men.[208]