This can be done through TSearch. Download in here
http://www.timsvault.com/cheattools/tsearch.zip1. Run NBA 2K10, and go to the main menu

2. Run TSearch

3. Open process button -> Choose nba2k10.exe

4. Click the New button

5. Add the following addresses:
Regular Season Length: 545B3EC
Conference Quarterfinals Length: 545B3DC
Conference Semifinals Length: 545B3E0
Conference Finals Length: 545B3E4
NBA Finals Length: 545B3E8

6. Change the values to get the desired season length
Regular Season
29 Games: 0
58 Games: 1
82 Games: 2
Postseason
1 Game: 1
Best of 3: 2
Best of 5: 3
Best of 7: 0

7. Freeze the values

8. Start a new My Player game

9. Save the game and Exit TSearch

NOTES:
- I wouldnt use this method with an existing game as there may be bugs
- Some milestones may be unreachable as they require a certain amount of games to be played