Okay, I've gotta jump in with a story here, although it wasn't a Volvo. How not to do a cam change on a '67 Chevelle SS396:

Park car by the curb on a hilly street. Drain coolant, remove radiator and grill. Loosen all rockers, remove pushrods. Remove intake manifold and timing cover, etc. etc.

Find that lifter are mushroomed and will not come out upwards. Start to pull cam anyway, and find that they easily fall into the pan. Continue until cam is out and all lifters are in the pan.

Note that pan cannot be removed with the engine on its mounts because there's a crossmember under it. Unbolt motor mounts.

Raise front of car with a bumper jack. Wedge some combo of cinderblocks and firewood under the crank pulley / harmonic balancer. Lower bumper jack until engine is as high as possible.

Crawl under car, loosen pan bolts, pry pan loose. Now there's about an inch between pan and block for fingers to go into. Spend several hours under there fishing for lifters.

For some reason, nothing collapsed and no passing traffic ran over my legs. Why, I'll never know.