Coffee spilled - keyboard turning mad - external keyboard usage?

Hi there,

I‘ve got a Macbook Air 11“ Mid 2011 (A1370), unfortunately I spilled a small amount of coffee over the keyboard, enough to have it gone mad after several hours. Sometimes it is all caps, sometimes CMD or other key being blocked, now the row 7, U, J, M are not working at all. I already opened, removed battery, sprayed Iso-Alcohol inside keyboard and logic board parts as best as possible, but didn‘t helped at all. I am worried and not experienced enough to remove everything to get to the keyboard and honestly the whole Macbook is so well used (i.e. nicks and dents, etc.) that I don‘t think it is really worth the effort, with limited chance to have it fixed.

To cut long story short, I at least need to format the SSD and trying to hook up an external keyboard (and bluetooth mouse), but if I connect an external keyboard now, the malfunction internal keyboard is effecting the external one.

So what have i to do to remove the internal keyboard and have the MBA work only with external keyboard?

Any chance? Right now I am not even able to log in with the mad internal keyboard :-(

Any help is welcome!

Thx!! Oliver