Coolant leak from Gasket, How to repair self?

which gasket firstly, you have a head gasket, thermostate gasket, water pump gasket, but for some reason I think you may be talking about a head gasket,(let me know which one) This type of job depends on your skill level, time, proper tools(dont get started and then have to go borrow some tools, loss of time) even for a novice this is no cake walk if you have a lack in any mechanical area such as following directions, or reading diagrams this may not be the job for you. If you do decided to do it yourself take a picture of the engine before breaking it down, set aside a lot of time, and patience, if this is a head gasket job the game of memory is very important. If it is a thermostate or water pump gasket leakage you might can handle it, but water pump gasket replacement may come with some tight hand position spots you will have to deal with and belts to remove, If it is a thermostate gasket it is pretty simple on most vehicles most times a DIY job. look out for accendentally breaking bolts and knuckles, good luck.