How to Install a Rear Wheel in Vertical Dropouts:
You’ll need a wheel and quick release skewer. Start by removing the old wheel from your bike. It will come off easier if you move the chain to the smallest gear on the bike. You may also need to loosen the brakes.
Loosen the quick release. The wheel should start to fall out right away. Once it is loose, grab the rear derailleur, and pull it towards you. This causes slack on the chain and you can pull the wheel out easily.
To put the wheel back on, pull the rear derailleur back, and feed the new wheel into the chain so it is on the smallest gear. Make sure the wheel is seated properly in the frame, and begin tightening. Start to tighten the skewer. Once you feel tension, clamp it down.