My concern letting someone else do the trimming, is that, when complete, the armor would not fit the owner. There is a lot of fitting to be done unique to the individual wearer.
I'm no expert on armour, but having just trimmed a set I have to agree - it;s really not too hard a job (ABS gluing the pieces is much worse.) and you need to keep measuring it up against yourself to make sure it doesn't pinch too much etc.
