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

Hire a couple of college kids--they need the $$!

Cheers!

Okay troops, how do you do it if there is no carton as in an in-home audition of a preowned amp, say a large Krell or Pass 350?

I actually have 100lb Emotiva XPR-1 amps that I move around when I rebuild them.  I use a standard hand-truck, but put a small hand-towel on the bottom plate.  Tilt the amp on so that it is on it's side and wiggle it onto the towel.  Strap the amp to the hand-truck if necessary. 

Hah, I watched those videos imhififan.  There was another video that came up just after it:

https://www.youtube.com/watch?v=wUbm1e1PdwI

The Northern tool 3-wheel type can help climb stairs, but it appears that it's harder to turn/rotate this type of hand truck.  A hand truck with big tires and sliders appears to work better overall.  An example:

https://www.amazon.com/Tyke-Supply-Aluminum-Climber-Handle/dp/B01ATY2HI4

Class D lol