Oh, I've had a few DBS bikes through the years! (DBS = "Den Beste Sykkel" = "The Best Bike". Well.) Which model is yours? I have never had to remove a crank, but they should be pretty similar to your Ashtabula cranks. The bearing cups are press fit and should be hammered out. I will have a look tonight and see if there is a diagram in my DBS service booklet. If so I'll post a scan.