Manipulating the game settings is the key to getting every achievement in NHL2k6 easily. These settings can be found after you choose your team in quick play mode. Press the Y button at the settings screen to access them and the bumpers to scroll through the different settings.
For this achievement, set the difficulty to Pro or higher, obviously, set all of the AI skill sliders down to 0 and all of the Human sliders up as far as they will go. It is also best to set the period clock to a full 20 minutes so you have sufficient time shorthanded to get the goal. It's also best to select a very good team for yourself and a very bad team for your opponent. Denmark seems to be the favorite team to beat up on.
Once the game begins, it's up to you to commit two quick penalties. There are two really easy ways to do this. One is by checking the goalie while he is holding the puck, or the puck is in play by skating up to him and pressing the B button. The other is to use the right analog stick to hook or slash your opponent while they have the puck.
Once you get two of our players in the box just score a goal. It should be very easy with the sliders adjusted. If you want to kill three birds with one stone, get the goal on a fast-break with a defenseman for 3 achievements.
As others have suggested, you can use a second controller to pull the opponents goaltender to make it even easier.