How do you resurface a concrete shotcrete in-ground pool?

Unless you have some experience with concrete or any kind of plaster, i do not recommend it. This is a ultra specialized trade. it takes years to become a decent trowel man. First, your pool needs to be drained, as soon as you can get to the main drain on the deep end of your pool, remove the cover and unplug the bottom of it. This is a very important step , in case you have a lot of ground water, the pressure coming from underneath of your pool must be released by pulling the plug inside your main drain. After that, you will have to cut right underneath the tile line, all the way around. Cut it in a 45 degree angle, about 2 inches wide. A good bath with muriatic acid is the next step. Use a watering can to pour it; be careful with the fumes from the acid. The final touch would be the use of a concrete mixer to mix the plaster. You can carry it with a wheelbarrow and dump it into the pool. Use a round edge trowel to pull the plaster up on the walls. This is a very concise description of this process. Like i said before, unless you have some skills using a trowel, it is better to live it to a professional pool plaster company.