Full Planning application

[MumToTooManyBoys]

I have to this to change part - use into full residential. Property is based in London but I'm not. Any recommendations on how I can do this? Who could do it?

Not quite sure what you mean - you want someone to submit a planning application on your behalf?
Just because you're not in London doesn't mean you can't do it.
A Planning Consultant, registered with the RTPI is your best bet. You may need an architect/architectural technician/builder to draw up plans for you. A Planning Consultant could advise.
I assume you own the property?