With your animation open (the whole thing) go to Animation--> Retime Animation and for SOURCE FRAMES put in the middle number say 60 the end frame of 135.  For the DESTINATION FRAMES put in 1 to (135-60) +1. You have to add the extra 1 because Frame 60 is part of the timeline and you don't want compress or expand the timing.  Then shorten the animation to 76 Frames which gets rid of the extra that are no longer needed. 

Poser 5, 6, 7, 8, Poser Pro 9 (2012), 10 (2014), 11, 12, 13