If you can actually SEE the egg, and there is no tissue surrounding it (or preceding it), then you can use forceps or tweezers with "grippy" ends to grab it. Once you have hold of it in the forceps, be very gentle, or you will just break it into pieces. (If that happens, I would try to clean out as many pieces as possible, and irrigate the area with water to try to remove as much as you can. Then feed her to stimulate the elimination of the remainder). The best way is to roll / rock it for side to side with a twisting motion. That helps to break any adhesions to the surrounding tissue. Continue gently twisting, while pulling it slightly towards you, getting an even better grip if you can, as the egg starts to come out. Also, use your thumb on the snake's belly to prevent the egg from going backwards.
If you feel that there is any tissue in front of the egg, then abandon your effort, or you could cause a prolapse. In that case, let the egg go, and try to guide it out with a probe so you can avoid pushing tissue out ahead of it. If you still feel tissue, remove the probe and try at a slightly different angle, until you contact the egg directly.