OK, heres the thing, I am trying to get a band going, I have a friend who plays bass, he said he could play this and that so I asked him to join the band, now, after two or 3 times playing together, I realized he cant even keep good timing, and doesnt really puts an effort on it, so how can I say.... I dont want you on the band anymore??
if this is not the right place for this, Ill understand. (Im new here ).
If he doesn't put any effort into it, he shouldn't mind when you point that out and let him go.
Just tell him you're sorry, but you'd like to play with someone a bit more experienced for band stuff. But you guys are still free to jam whenever and you can give him some tips to get better.
And no, Guitar Hero will not help. Even on expert. Really.
Alan you are like Yoda.

Yep that is perfect advice and has happened to me before. Now this guy (and yep he's bass too) sounds a bit more motivated though as he is going off and practiceing and learning and so I will do a little side project with him in the future.

As Alan said, find someone else but still jam with your friend and help improve. Sometimes lack of motivation is because he is fustrated because he is finding it difficult to make improvements on his own. Help him through this.
"Just because you can, doesn't mean you should."