With enormous difficulty and a certain amount of luck.

Limewire have not extended themselves to make a chat feature that is much use, and often even if two users have chat enabled and try to chat they probably will not be able to. The technical reasons for this are beyond my grasp.

Also consider this. A user may have chat enabled. This seems to make it easier for others to browse his/her share, but may well be nowhere near their computer for hours on end so will be unable to respond if you sent a message.

I would greatly like to be able, at least, to send a message saying "Your Grateful Dead file is in fact Doris Day" Yes ... it has happened.

Forgive me if you wanted to know how to enable chat .... I assume you have worked that out already and found that clicking on chat usually produces no response. One day a dialogue will actually come up! and if you get a reply ..... that's what I meant about the luck