There are probably a few good videos on the web. There are also kits you can buy that really make it easy and convenient.
I do it all myself with my own materials.
I use a toothpick to scrape out all the gooey seal material from the tracks. If the back can be removed easily, this helps when orienting the camera at an angle to prevent particles from falling into the shutter area. Even so, I use tape and paper to cover the area where the shutter is to protect it.
Afterwards, I use isopropyl alcohol on a fine cotton swab to clean the tracks further.
For new seals I use a bottle with a fine long needle to lay out Pliobond in the track, then use properly sized yarn material as the new seal. Be aware of the gap and the little lever in the top track of most cameras where the exposure-counter reset mechanism is.
There's usually a pad along the hinge side as well that will need to be replaced.
For the mirror damper, I first place a small soft microfiber cloth or even lens tissue over the groundglass to prevent any particles or adhesive from getting on the groundglass. Then with a fine blade I remove the old mirror buffer material and clean it off with isopropyl alcohol. Again I use Pliobond prior to putting the new buffer foam in place. It helps to have a fine curved tweezer-like tool to place this material properly and then apply pressure. Some mirror buffer pads need to be cut in two because there's a little screw in the middle that you don't want the pad to cover. Sometimes finding the right buffer material can be a challenge - someone suggested mouse-pad material, but I find that it deteriorates very quickly.
It helps to have a very bright light and a fan for ventilation.