can squirt a little bit of home made saline up there to loosen the snot......if it's not very runny and suck it out with the nose ball thing. try to see if any snot comes out first before adding any saline up there. you can also drip breast milk up there, i think to help loosen it and suck it out.
Use the bugger sucker regularly to suction out as much as you can. Little Noses makes a saline solution which you can drop in to the nose to help. Also, sleeping on an angle...like in a swing or bouncer seat will help.