Well...I'll try to help, and hopefully it's not different than the standard variety.
I'm thinking this lock may possibly be a bi-directional wafer lock. This is where a double sided tension wrench can come in handy. The tension wrench is shaped like a "Y" with the top forked portion placed in the keyway. You'll need to rake the wafers on
both sides while applying tension clockwise.
If you have one a small diamond or better yet, a half ball pick should work well.
At the very worst this may be a normal wafer lock which you would rake towards the exposed wafer side only. A few good rakes should open this lock easily.
Lubricate this lock well with a silicon/teflon lubricant before picking.
With your pick, before you even attempt picking, place it as far into the lock as possible and press downward. Slowly draw it outward and count the clicks...this will tell you how many wafers are in the lock..there should be 5.
I hope this isn't too confusing.
