GGoodwin
Tap the sear pin out with a nail used as a drift. File the tip of the nail flat so there is a nice flat surface before you start. If you use anything sharp, you risk deforming the end of the sear pin. You don't have to take the sear pin all the way out. Just drive it out far enough for the latch to clear the sear pin. I did not have much trouble driving the sear out once I found a good nail to use as a drift.
When you remove the nail after driving the sear pin out of the way, the latch will want to spring out, so be careful not to lose it or the spring.
A poor man's technique would be to cut the slot in the latch just slightly deeper, allowing the latch to further engage the lug that is dovetailed into the barrel. Stretch the spring so it bears against the latch with more force. I would say this is not desirable over replacing the parts with new stuff. It'll just get you shooting again while waiting for the replacements to arrive. (From VTI that is only about four days.) Plus..It is fun working on the pistol.
When I answered your post, I did so based upon my own experience but there is a second possibility, a second possible source of the problem. It is possible (but I think not very likely) that the lever itself is worn in the area of the screw that holds it in the barrel. I have never seen this on any of the pistols I have worked on (which is not many) but it might be a good thing to check. Just take the lever screw out, take the lever out, and then examine the hole in the lever and the screw itself. Any wear should be obvious.The hole will be deformed or the screw will be obviously worn. I doubt that you will find such wear, but again...It is fun to do and it is worth knowing about the condition of the pistol.
Unless you note some wear or some deformity of the lug, I would not replace it. As Finger's says, it is easy enough to do and it is not an expensive part. (VTI - 6.00). If the latch is also in good shape then you only need the spring. I would buy a spare sear pin as well. It is not listed on VTI's parts list but they probably have them. Dixie Gun Works lists the part as MP1804 - $3.50.
If it was me, I would get the sear pin, the spring and the latch.
BTW, when you put it back together, make sure the latch is installed in its original orientation. It will go back together two ways. The bearing edge should be towards the floor.