They can already be made real.

A) Make sure your ship is bigger

B) Shoot a ton of highly charged electron beams at the enemy space ship to ionize their hull

C) Magnetize your hull to the opposite charge and bring in the ship

How does one go about decelerating the other ship before it smashes into yours?

D) Magnetize your hull to the same charge and bring in the ship

The other ship would have momentum in the direction Of you. I suppose you could swap your hulls charge to repell

Change your ship's charge so that it's the same as the pulled ship, maybe?