I thought I could just add a pound or two to the tank, because the water pressure in the house was much lower than the one it replaced then I tried to take it back out.. so now I need to know the steps to safely empty and refill

It's simple. First you will need to find the cut in point. This is the pressure at which the switch turns the pump on. Turn on a faucet, then watch the pressure gauge. As pressure slowly falls, you will hear a "click" from the switch, turning the pump on. Let's say, for example, that it clicks at 30#. You will then turn off the system and allow pressure to completely drain off by opening a low level faucet. When pressure is at zero, you will then set the tank pressure at 2# below the cut in point. In our example, that would be 28#. Once that is done, then turn the system back on.

Adding or removing air from the tank, once it has been set correctly, is never needed in a properly functioning pressure tank.

Thank you for this information, I will try to utilize it. I will let you know what happens :)

Would like to point out that when jlisenbe says "When pressure is at zero", he means no actual water pressure. Pressure gauge will still read some pressure. Right, jlisenbe?