Title please c: song goes from 160 to 150 to 130

what ive done is to select the beat marker where the 1st change occurs, then in the beat menu alter the bpm. that will alter the bpm from that point onwards to the end of the song. you can do this as many times as you like, but u may want to manually adjust some of the beat markers for a more gradual change until the point where the new bpm settles.

 

 I hope that makes sense

This helped, thanks!

http://customsforge.com/topic/856-tutorial-for-proper-gp-tab-sync-sectionphrase-authoring-and-more/

 

This thread could help you out too.  I had to use this for a song that started off 210 bpm then went to 105 during the chorus and then back to 210.