Any experienced Volvo dealer tech, experienced with Volvo engine work will have the proper tools at that dealership (required by Volvo for ALL dealers to have) AND also be able to correctly re-assemble the engine. If you've already got bent valves for some reason, they'll need to be replaced. If someone on the phone is telling you otherwise, that person is full of it.
Note, try asking a dealer tech at any dealer as there are often people who answer phone calls at dealerships who have no clue as to what goes on there (unfortunately).
They won't tell you how to fix your car or what tools you'll need but if there car is towed there, they will be able to fix it.