You could go to the club in question and then click teams, then click Destroy team. I don't know what this does but I'm sure it isn't good.
Alternatively go to the teams finances and then put them into debt by editing balance, put their transfer budget to zero then remove any sponsers and add a few loans outstanding.
Also, take their wage budget right down too and whack a few million on to their stadium rental, you could also add a transfer embargo on the same screen.
I thought about doing it with spurs but then realised that they are crap anyway so didn't bother.