From thesis text to slides. How to ease the process?
You have to cut down brutally. You will have a half hour or so to show the work of a year or more, that is hard.


Explain what this is all about. A short introduction/reminder (depending on your audience!) is probably needed.
State your objectives clearly. One slide for this should be enough.
Summarize your main results. You won't be able to cover everything, but make sure you show enough to cover the stated objectives. Perhaps highlight some tricky point, or a neat technique.
Summarize your objectives again, explaining how they were met.
If pertinent, point out possible future fruitful work building on your thesis
It might be useful to have a slide with publications resulting from the thesis, both already published or in the works (submitted and waiting for approval).


You might consider having some "spare" slides with more details, on which you can fall back when asked to elaborate.