CB,
Well, I have an O'Day 26 and trailer it around pretty often a few times a year anyway. I move it to a lake for a week vacation and sometimes to a large lake near me as well. it trailers well, and with a decent pickup no issue hauling either. As with what others have said, it is doable. I do not have a roller to mess with so that makes it easy as well. I step the mast with only myself and whatever friend I can grab to do it. I looses the head stay and drop her gently. No baby stays and so forth. Teh mast is pretty light its a matter of working against the leverage is all. This year I am making a gin pole solution, taking a 2' alluminum pole 8' long attaching to the base of the mast, and then will either use my traveler pulley system or attach a winch to gin pole to raise and lower when i am alone. The side to side thing has not been an issue as i walk it down. So far so good. I know I hear the folks say I am tempting fate and one day might drop it, but I am cautious and take my time. However, doign it with two guys takes a matter or minutes vs hours. I leave the back stay connected as well as the side stays and when I lift her ni place one of us holds it there while the other goes forward and reattaches the head stay. Tighten and she is up. takes moments to do. it is not a big issue at all.
i have seen many gin pole variations and the worse I helped a guy use one that took us two hours to set up and 30 seconds to raise the mast and another half hour to derig the gin pole! tehre were four or five of us standing there helping and we could have had the mast up in moments, it was quite absurd. However I do appreciate safety and ingenuity as well.
But, getting back to it, a drop the mast tie it off to the rails using pipe insulation on the rails and then use rolls of shrink wrap for tying everything up and off I go. when I get to my destination cut off the shrink wrap, slide mast forward pin and raise and pin the headstay. I am on the water in under 30 min. when traveling I leave the main sheet in the boom, so I only have to reattach the boom. Then feed the slugs to the mast and attache tiller and rudder and motor. with two of us and having done it often we have a rhythm. However when all is done there is one last review to see that all pins re attached and safety clips are on them! Lost a rudder one time that way, cant be in too big a hurry anymore.
Safety is my number one issue and so far with that in mind I have not had any issues stepping the mast and heading off to waters afar. The gin pole will be if I am alone and have no other option, but to date if I am in a pinch I have asked bystanders to assist and so far they all great it with enthusiasm as most people I find are quite curious about how a sailboat is rigged. So they are more than happy to step up and help lift the mast.
One a group a burly looking bikers showed up at the launch to see what was going on, and I quickly put them to work

One of my brothers is a biker so I have some idea of their thinking
Bottom line, I have no qualms about stepping the mast myself, and can manage with one other person. maybe one day that wont be the case as I age and my back might not be as strong as it is, but for now it works.
Next year i will venture out even more, I have a desire to head down the Hudson River to NYC from Albany and from Albany there aren't any bridges to worry about clean shot all the way down. Then once in NYC I will have my car driven down and haul her back home as the current and my vacation time might not allow a return trip via the river.
So, I would say to you with the O'Day 25 it should not be an issue whatsoever. You have heard it said before, "if I can do it anyone can" and that holds true here as well.
Happy sailing.
Bill H.