yes, the game will take LED's, BUT you will need to either modify the existing lamp board or get an alltek board. There are adapter kits that make modifying the existing board easy.
Without this, your lights will flicker.
You do not have to unscrew all the lamp sockets, just bend them back to put in the new bulb.
Note: putting 555 led bulbs into the white plastic Bally sockets is a real pain! I found that pushing them straight in works best. You'll find out what I mean.
Wiggling them side-to-side will be very frustrating.