I give you a step by step guide on how to change the washer in a tap and show you what happens to washers.
You will need some tools I list some here below and BE WARNED if you get this wrong you can flood your house. So the water needs to be turned off before you start and you do need to know what you are doing.

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It is always great to have some tools on hand. Here are some good basic pieces.

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Drill Accessories, bits and screw heads: https://amzn.to/3NDm69s
Set of small Pliers: https://amzn.to/42tqaOR
Long Needle Nose Pliers: https://amzn.to/3WZZ68F
Stanley Basic Tool Kit 65 piece https://amzn.to/2SmxN6a
Stanley Basic Tool Kit 210 piece https://amzn.to/2QAukUf