you can get a thin c spanner from Harris performance, its the genuine Ohlins one and ain't too badly priced, get 2 and you can lever against each other to loosen the top nut and it is possible to adjust pre-load with them but be prepared for scraped kuckles. I haven't bothered with the hydo unit, its expensive and heavy its only 4 bolts to drop the shock out so easy to do if you do feel the need to mess about with it. I have an extra heavier spring just in case I convert to bip rather than using preload, it don't take long to do. Using the hydro means you need a spring compressor to swap springs as well
