On the main screen type "CODE", a prompt will appear asking you to enter a code. Enter any of the following codes:
"CODE"---------------A list of cheats will appear
"BIDS"----------------Erases all bids from memory
"LIMI"---------Disables the 110 team rating limit
"BEST"-----------------Gives you the best players
"FREE"--Enables managers to buy your players free
"POOL"----------------Saves European pool to disk
"VIEW"---------------------------Programmers tool
"PROM"---Last season's promotions and regulations
"MEMO"----------------------Show available memory
These last couple are activated by typing them in on the main screen without typeing "CODE".
"EDIT" to enter the full editor. Now press 'W' to enable you to manage any team. A small green and yellow strip should appear just along from the LOGO and AUTO icon things, under the second logo space. You can now go to the Manager's menu and JOIN any club. Your rating automatically jumps to that of the new team, unless you are joining a lesser club.
If you want to alter teams because of transfers among Premiership and Division 1 teams, to maintain more accurate club records, instead of creating a whole new player in the editor, it is best to make yourself the manager of the club who bought the player, enable "FREE" transfers, and transfer the player that way. This means the player keeps his original ID number.
For example, Paul Furlong was bought by Chelsea from Watford, so to enable this change, simply become Chelsea manager, enable "FREE" transfers, and approach Watford.