delete comments of a certain post

hello!! would like to know how can i delete lots of comments of a certain post/page. it’s because i have a website, Noticias Automotivas, and it is about cars, but as i am a huge fan of dance music of the 90’s, i have set a page about it, which is Dance Anos 90, and as people can’t find stuff about this, in portuguese, the page is being very successful, with more than 450 comments…. but lots of people access internet through dial-up connections here in Brazil, so.. they are complaining…..

I appreciate your help with this!!