How to physically move large heavy 100lb amplifiers easily (up and downstairs)

Get your wife to move it!
Seriously though; I'm lucky as I'm still able to move up to 200 lbs. by myself. I just carried two Pioneer speakers up a long flight of stairs. I was huffing and puffing a bit, I admit.
I can't see hiring two young people to do the job. I can picture it already. BANG, BUMP! DROP!
 I have a scar on my arm from where my Pass 250.8 heat sinks dug in when I picked it up.Oh the dangers of being an audiophile/

I have similar problems moving equipment from my lab to my music room. Forty pounds with a dolly is my absolute limit. For the 90 pound platter and 100 pound speakers, ALWAYS use movers. ALWAYS.

There's something called a "laddervator". I've seen roofers use them, and the Dutch use them when moving. I've never seen them used inside one's home, but perhaps their are smaller ones one can rent:
https://www.sunbeltrentals.com/equipment/detail/1207/0440215/ladder-platform-shingle-hoist/
 

With absolute caution. I was moving 150lb Pass monos last week and a heatsink sliced a nice 5” gash in my leg.

If going downstairs, why not take a page out of the courier company’s handbook, .....just push and watch it tumble down the stairs.