Help with themes? and IM program?

[blkout01]

I have the Mogul 6800 running the Spb mobile shell 2.0...but would like to try putting some different themes on the phones display...I have the tsk files but dunno what to do from there.?. I also have the theme manager but if I try to import the tsk files in there they don't show up...Keep in mind I'm pretty noob to this, so if it's something simple and stupid sorry.
Other question...what's a good IM program to use, I mainly use yahoo thats my main interest, I've used the web im based program but want to use an actuall app. Thanks for any help