iMac help

[putthesneckon]

My DF's friend passed away recently and we would like to buy his iMac. His DW has no interest in technology.
My DF has brought it to us this weekend, however we do not know his password. He appears to have put MacKeeper on it but we need the password to remove it.
We are Apple virgins

Do anyone of you know if we can sort this or should we just say No Thanks?

TIA

Googled yr problem and found this, it may help, if not google it yourself and see if you can find another solution. Best of luck.
iMac

Thanks widower
We spoke to Apple who were very helpful and did a full reset. It's all working like new now.