Help with DBComander

I ve got the program and its working fine but I dont know how to do some things for example:

Change ratings for all centers at a once
Change starting lineups
Trade players

Can somebody help?

1 cant do it

2 change the rosterpos fields for those players (0-c 1-pf 2-sf 3-sg 4-pg)

3 change the two players team field to the team they're getting traded to and change thier roster position if needed

When I go into appearance file to change the height or weight of anyone, any change makes the player become 6'3" and 176 LBS. No matter what I change these to, once changed the height and weight seem to be ignored and it's 6'3", 176.