Brake pedal goes slowly down?

Replacing the master cylinder isn't a difficult job. If you take your time, you should have no problem.

To get you started, here is a link that shows in general how it is done. You can use this as a guide. Here are the master cylinder installation instruction you have requested. Here is a guide to help you step by step with instructions in the diagrams below to show you how on your car.

https://youtu.be/WDxvEQrMkBg

and

https://youtu.be/w7gUsj2us0U

and

https://www.2carpros.com/articles/how-to-replace-a-brake-master-cylinder

Check out the diagrams (Below). Please let us know if you need anything else to get the problem fixed. If you look at the attachments below, they include the procedures for the removal and replacement of the old one.