If the floor is slanted, be careful of a runaway. It does not take much. For 3500 lbs I recommend 4 people, it has a lot of momentum to stop. I prefer bars made of solid steel, pvc and pipe may work, but at some point a lot of weight will be on 1 pipe. The key is a super heavy duty pry bar. Lift up one edge as high as you can, and slide a bar to just before the middle. You now have a very heavy unbalance teeter todder. Makes it easy to lift the other side and get a second bar under. Place a third bar just in front of safe and roll it on to it. Continue as necessary. Moved my friends 4800 lb safe that way a few times. We has 4 people and it was a struggle. Angling the bars to turn is a skill and may take a few times to learn.