i used to have to do a few of them a week when i ran a shop
im assuming you know to get the bead in the centre of the rim at its deepest point ?
ive never liked using levers
i start by having the tyre on with one bead
put just enough air into the tube so it isnt completely flat
stick it in the tyre
poke the valve through the rim
pop the tube so its in the centre of the rim
start seating the bead from the valve
at about halfway push the first half of the bead into the centre of the rim and deflate the tube a touch
keep pushing the bead into the centre of the rim and deflating the tube a little at a time until your thumbs are aching and you push the last bit on
make sure the bead is evenly seated all the way and inflate a bit , check again and lastly put to desired pressure
have a cuppa and mutter to yourself about proper roadies having multiple sets of wheels
"It also has a seat. I don’t use it, but you probably will for the first few years until you build up the muscle."