Player modification q's

Hi, just curious to see if a couple of things are possible.
Firstly, I'm wondering if it is possible or not to modify which team a player is signed to outside of the game. I.e, if I wanted to multi-edit a large number of players and move them from Team A to Team B or assign a lot of FA's to different teams, could I do this within an exported list of players and then import an updated list? I've tested exporting players, changing team ID from say 0 to 1 in the csv, then importing this json list of players who have a modified team ID. This doesn't seem to do anything however and the players stay on the team they were on or remain a FA. Is there a different way to do this or is it not something that is currently possible?
Also, is there a way to delete multiple players in one go from the game? Deleting one at a time is fine, but is there any way to select more than one player at a time and then delete those in bulk?
Thanks
Firstly, I'm wondering if it is possible or not to modify which team a player is signed to outside of the game. I.e, if I wanted to multi-edit a large number of players and move them from Team A to Team B or assign a lot of FA's to different teams, could I do this within an exported list of players and then import an updated list? I've tested exporting players, changing team ID from say 0 to 1 in the csv, then importing this json list of players who have a modified team ID. This doesn't seem to do anything however and the players stay on the team they were on or remain a FA. Is there a different way to do this or is it not something that is currently possible?
Also, is there a way to delete multiple players in one go from the game? Deleting one at a time is fine, but is there any way to select more than one player at a time and then delete those in bulk?
Thanks