No tongue that can lift? You know, the part that attaches to the ball on your car. (You actually do the lifting! It's a bit of a grunt but should be easy enough if your trailer/boat weight is balanced. No, you don't really push it into the water very far at all, in fact when you're done you should have the trailer wheels basically at or near the waters edge, then you can just hook up and drive off. My trailer has permanent/stationary runners/bed, no rollers. With a boat that light you really don't need them to do this.
So, just back up as usual, get the trailer wheels maybe a foot or two in the water (or just do it on the gravel/sand), unhook the boat from the winch, push it down the runners a bit (with the motor up

), then unhook the trailer from the ball, push the trailer a few feet away from the car (just in case!), lift the trailer front/tongue and push on the boat. The weight will shift the boat to where the trailer wheels act as a pivot, at that point you drop the transom onto the ground and start working the trailer out from under the boat being careful to not let the bow drop or the trailer lift out of your reach. It's a bit tricky, but if you're careful (and a young buck!) you should be able to do it easily. Only thing to watch for are your wood runners, if your boat is weighted down with gear it can bend them and possibly break them. But, I have a 15.5' deep 'v' old (1955) alumacraft that is a tank and I've done this by myself without breaks or problems.
Reloading is super easy, actually less work that getting the boat off. When you attach the winch and start cranking the tongue of the trailer will lift off the ground, this is where you need to control it and keep the trailer straight and let the tongue go up so the boat slips on easily, don't worry, once the boat is on the trailer far enough the weight will balance and the tongue will start to come back down. The thing is you can do this on dry land, I do it in my back yard when I need to work on the trailer. Just be sure you are able to pull the boat into or out of the water by hand. If you can do that then it doesn't really matter where you unload it as long as you can keep control of the trailer as it slips out from under the boat when off-loading! (actually, a sandy launch is even better cause it will forgive any mistakes you make a lot better than a cement launch!) You may get a little wet, but if you have rubber boots or waders then no problem. It's not that hard but you might want to give it a dry run first. I learned this from a guy at a marina in Webb Lake, WI when we bought our alumacraft. He loaded it onto our trailer this way, and unloaded our 12' this way. He actually does this with his 16' Lund! :shock:
Looking at your trailer pic, you might want to put foam rubber padding on the trailer frame where it comes to a V in the middle near the motor, that is likely where your boat would drop off and push up on as you try this technique. Also, is there any way to drop the height of your runners? In the pic they look like your boat is up a good distance from the trailer frame. If you can lower those (at least in the rear) that would help a lot.
Oh, did you mean you don't have a thingy on the tongue that swings up and down to roll the trailer around without being hooked up to a car? IF not you should still be able to do this, but rolling the boat on the trailer is more difficult. YOu might want to invest in that! But, seeing as it is a smaller boat, you're a strapping young man, and there should only be between 100-200lbs weight/pressure at the tongue fully loaded (for trailering safety!) anyway, you should be able to maneuver the boat and trailer by hand. But, one of those trailer jacks (I think that is what they are called) would help you a lot! Being able to do this tech opens up so many smaller Northwoods lakes that it is so much more valuable to me than a big and fancy bassboat IMHO.