All-Time Boston Celtics
You need to place the .TMM file in your SAVES folder typically located:
C:\Users\Your Name\AppData\Roaming\2K Sports\NBA 2K12\Saves
Then run NBA 2k12 load the roster you want the teams located in, then load the team.
Enjoy - share/distribute/edit as you would like.
All-Time Boston Celtics Roster:
PG-Bob Cousy
SG-Paul Pierce
SF-Larry Bird
PF-Kevin McHale
C-Bill Russell
6-John Havlicek
7-Kevin Garnett
8-Dave Cowens
9-Robert Parish
10-JoJo White
11-Tommy Heinsohn
12-Dennis Johnson
IR-Ray Allen
IR-Nate Archibald
IR-Antoine Walker