transfer of ownership/ mortgage

[shcoga]

Myself and my partner took out a joint mortgage 2 years ago, we have since split up and my ex partner has not lived at the property for 1 year and has not contributed towards the mortgage since he left. Whilst my mortgage company say they do not need his signature to remove him off the mortgage a solicitor will for the deeds.
I do not know where he is and so therefor this would be impossible.
Is there a way round this? and if they manage to track him down any ideas roughly what he would be intitled to?
The mortgage has always been paid on time for the 2 years and has always been paid solely by myself from my own current account.