As far as I can see, they have four options:
1) Make no changes. I don't think this is really an option. They wouldn't have goten legal recognition in several European countries if they hadn't weaselled on the blood issue. The generation teaching was getting unsustainable. The civilian service position created a major deterrent for young men to join. Etc.
2) Continue the current path of non-apology apologies whenever they have to make a change, and take the losses. This only works if they can continue to bring in new members (through foreign language groups or whatever other method) to replace the old ones who leave or are discouraged by the changes.
3) Ramp up the apology a little bit. This would only work if it's combined with a subtle, overall softening of the dogmatism. This might lose them some people, but IMHO it would enable them to keep more of the waverers, and even a lot of the stalwarts would find it a very welcome change.
4) Do a Worldwide Church of God-style mega-apology. This would be the most honest and appropriate thing to do, but it would suck from a membership perspective. When WCG did this, they suffered major schisms.
I think their best bet--purely from the perspective of retaining members--would be #3. It's the course that most new religious movements take--gradually softening and going mainstream over time.