Leaks out if the servo cover

[Tristansgn]

I just got my trans back from being built, went for a cruise around the block for the maiden voyage. Came back and there's a puddle under my car! I put it back on the lift and it's leaking from the servo cap. The person that put it all together lives about an hour away from me and said I can bring it back, but it's hard to connect with him...so should I just take the snap ring out and check the o ring, or could it be a bit more complex than that? Should i just bing it back to him and let the "expert" fix it?

 

[77 cruiser]

O ring might have got nicked when he put it together.