What type of screwdriver do I need to open the NES?

It is possible to create a dual-type Eeveelution such as Dragon/Ghost type, as it is your creation. Though Eevee currently has no dual-type Eeveelutions, this should not prevent you from...

No, you could also use your thumbnail, a butter knife, or some other flat, slim object to pry it open.

Use Trevor, as he can use his own hangar if you've progressed far enough in the story to unlock it.

Blow into the cartridge port, get a Q-tip and clean the connectors, then plug it in. If it fails, you've probably got a broken game.

Take the controller to the hardware store and show it to an employee there. They can show you which screwdriver you need to buy. Your only other option is to...

This could mean that you missed a word, or you messed up while typing. When this happens, you have to retype the word where the highlighted letter starts. Another possibility...

Maybe get new cables, or maybe even entirely new parts. Maybe take it to a technology store and have them look at it.