Editing Animation


I have a Problem and i cant find a solution!

How can i edit a Animation? i bought from Marketplace fighting Anime pro set.

The lower kick is 0.9 sec Long. but the character hits allready at 0,25 sec. so i would like to slow the Animation from 0.0 to 0.25 and the rest should normal. i just can slow the whole anim. but i dont Need this!

can you help me pls? is it Event possible? or should i use some other Programms?