Yamaha pf 70 key problem

[drahuber]

I have an old pf 70 that is still working well except 2 keys are sticking. I have taken 2 keys out but because of the little metal spring cannot get the key back in. I did this once before years ago and took all the keys out to clean them.
Question; is there a way of returning a key , with the spring without removing all the keys. I do not have a service manual.
Thanks
drahuber