First, you need to be in week one of the regular season with no games played or simulated. Otherwise, you cant load / create / edit the schedule.
Now, save the franchise file to you AR. Transfer the file from the AR to your PC. (I'm assuming that you obviously know how to transfer files to and from your PC)
Go to your programs folder on your PC. Go to Datel > Action Replay Xbox > Saves. Now, simply copy and paste the franchise file onto your desktop. Dont delete the franchise file in the saves folder until after you pasted it onto your desktop.
Open Finn's editor. Click on file and then open. Select the desktop option located to the left. Click on the file and then click open. You should now have the franchise file on screen starting with the 49ers. Click on the schedule tab on the top left. It's above the "SF" logo. Click "load schedule". Select the schedule that you want and click open. If you're not going to do any editing of the schedule, click on the "teams" option on the top left corner. This will bring you back to the 49ers roster.
Click on the "x" that closes the file, NOT the editor. You'll be asked if you want to save the file. Click yes. Once done, close the editor. Now, hook up your AR to the USB port and open up the AR program. Once opened, drag the franchise file over to the column on the left. It will save to the memory card automatically. Once done, close the AR program and remove the AR from your USB port. remove the memory card from the cord attachment and plug it into the Xbox controller. Now, load the franchise file in-game and you're ready to play.
Hope this helps.