So you're job is to get clips that you think are worthy to put in the montage. Now the more important part finding an editor or doing it you're self. Editing is no easy task and you will have to pay for some programs to do it you're self. Or you can ask around on youtube or random forums for a guy who will do it for you. Some might to it for free some you might have to pay.
Adobe After Effects is what I usually see a lot of people use. Just a quick note editing is no easy process and it will take you a long time to figure it out plus the program costs a good amount.