mxm files

I've never seen that extension before, but a quick google reveals:
http://filext.com/file-extension/MXM

Do you use this mixmeister software then? Alternatively, do you have the songs in mp3, wma, ogg or other music formats?

yeh i do use mixmeister is that the reason i have all those mxm files?

do i have to delete mixmeister to get rid of them all or is it safe to just manually delete the mxm files . ?

Well it depends. If you are using mixmeister for a reason and you need those files, then don't delete either.

If you have copies of all the files that you can listen to outside of mixmeister, then I'd suggest you don't need mixmeister, so you can uninstall that and then delete all of the files since you'll have no program to read them - but i repeat, only if you can listen to your music through some other player