1. Enough air in tube to hold some shape, insert tube into tire.
2. Put valve stem into hole (moisten to get through rim strip if nec) and mount one bead/side onto rim.
3. STARTING AT FURTHEST POINT FROM VALVE start mounting 2nd bead, pushing in both directions around toward valve stem. Check to make sure you can't see tube under bead of tire, if so just roll tire back and forth in that area.
4. When it starts getting difficult set wheel on ground (valve down) and go back to beginning, pushing bead toward center of valley and "scrubbing" toward valve again.
5. Using thumbs and palm push bead over rim until mounted.
6. Push valve up into tire and then push tire down to seat. Check again for tube under bead.
7. Pump to about 30-40lbs and check bead line (raised ridge near bead) to make sure it is the same distance from the rim all the way around. Deflate and recheck until OK.
8. Inflate to full pressure.

Optional but helpful to you and mechanics - mount the tire so that the label showing correct air pressure is at the valve, on the right side of the bike.

I have taught literally hundreds of people to mount tires in mechanic courses and consumer clinics using this method. Even though I had been a mechanic for several years I did not do the "valve stem last" until John Forrester (Effective Cycling) explained the advantages and I saw for myself how much easier it is. Almost never requires levers, even for an amateur.

Got to get this on Utube some time.