Do you mean that he removed both cam gears from the cams and didn't mark ANYTHING (not even the cams themselves)? If so, there's absolutely no way in hell that you'll possibly guess it right w/o use of the special cam positioning tools that only a dealer would have. You can order the tools through a dealers parts department but I doubt that any dealer will lend them out.

I'd be scared, VERY scared if anyone calling themselves a technician forgot to mark anything of such obvious importance. Also, being that the lifters are cheap (like about $160 for a set of 20, newest style which I've recently priced myself), I would never consider only replacing 5 out of 20 with all that apart. I hope you have new cam seals, the correct liquid gasket (not silicon sealant btw) and the 5 large spark plug hole o-rings?
With the 2 cams correctly positioned and held in place using the Volvo special tools, the correct proceedure to re-assemble that uses yet 2 more special tools to draw the upper cam cover down until you can install all the bolts and torque them.
I'm sure someone, somewhere has done this w/o the special tools but being that I work in a dealership and have done it by the book several times, I wouldn't consider doing it any other way.

If you want to see how it's correctly done with pictures of the special tools, you can order the OEM Volvo engine overhaul manual from their literature # 800-25-volvo.