Hi newcomer and welcome to the Tom's hardware forum.
1- Unplug the power
2- Discharge your body touching the case of the PC, and keep touching this while you change the components.
3- Read the manual to know the steps to change sucessfully your components.
Don't wear many layers of clothing...especially don't wear synthetic and natural fibered clothing together since that'll create A LOT of static electricity.
Just wear a cotton T-shirt to be safe. If you want to be extra careful and you don't have an anti-static wrist band, wear rubber/latex gloves. (the cheap thin type that you can buy by the dozen)