Grand Casino Arena is located at 199 W Kellogg Blvd, St Paul, MN 55102
The 'stagedoor' is through the media public entrance under the skyway to the right of Gate #1 (the Southeast Gate).

There is a security callbox near the employee entrance, if the doors are locked.
Security works off a list from the call stewards. Be prepared to identify yourself (knowing your list number helps them find you faster), show ID, and go through a magnetometer. If you have a bag it will need to go through x-ray or be checked by security and tagged with a wrist band.
If necessary, explain that you need your tools for work
Then go to the security desk, which is at the far left end of the public entrances.
You will be expected to wear a provided wristband.

If you are there for a load in, you can probably walk straight ahead and take the steps down to the arena floor.
Then walk to your right, through where the seats have been removed, and once off the arena floor, again turn to your right and find the crowd. You will be far backstage left. Ask where you check in.
If you are there for a load out, after you clear security, take a right and walk till you see the ceiling sign below.

Take either of these two elevators to the arena. The operators will be checking for your wristband.
Leaving the elevator, walk straight out, and once backstage, turn left and walk to the check-in area, again far backstage left.)
(You will be crossing backstage and, during a show, security will not allow you to loiter there.)
Be professional. Get checked in there (or you will not be paid) and stay near the check-in area until given further instructions.