You can do it without removing the shock, but it is a tight fit because the needle assembly is quite long. It also flexes a lot, so it will be a lot easier if you had someone to hold the pump while you inserted the needle, and someone to hold the needle while you pumped.
The opening is tiny, so be careful not to bump the needle on the walls; if you do, make sure there are no burrs on the needle tip before inserting it into the opening.