It’s possible.
I typically set ours to 20k, 70k and every 70k after that received an extra life.

First, turn OFF machine.

Now open machine and find game PCB and flip dip switch 4 to ON, on the game board.

Next turn ON the machine. Game will now boot in Test Menu.

Continue pressing player 1, button 2 until you get to the Dig Dug Adjustment screen and make changes on screen. Press Player 1 start button to save changes.

Turn off machine.

Switch Dip Switch 4 back to OFF.

Turn back on machine and enjoy

FYI. Be sure Dipswitch #3 is in the ON position. This dip switch will allow the game to save high scores even after being turned off. You’ll want those bragging rights with your girlfriend to remain everytime you turn the machine on

Yeah that’s not cool.
I spent several minutes writing you a very step by step instructions of how to do exactly what you asked for. I wrote it in a way, I thought a “newbie” could understand it. Guess I was wrong.

One thing you mentioned you didn’t understand was the dipswitches, which several others followed up with an explanation as to what they are and where they are located on the game board.

You follow up with the above comment? Geez. Why ask for help if you don’t want it.

Thanks for wasting MINE and everyone else’s time.