After time, many laptop display screen show symptoms such as the one you're seeing. The fix is to replace the screen, plug in an external monitor and use that, or buy a new computer. Here, if the laptop is under warranty, we have the manufacturer replace it. If it's not under warranty, then the laptop is normally too old and screen replacement is not worth the money. We replace the entire laptop.

In regards to steps for replacing such a laptop screen, Google usually gives fair instructions PLUS it would be a good idea for you to check on the price of parts plus the availability of tools to perform such steps. That usually tells you the worth of going through such procedures.

Hope this helps.

Grif