Make a backup of your 1.0 songs and sample kits. 2.0 is backwards compatible with 1.0 songs and kits, but 2.0 songs and kits are not compatible with 1.0.
Then install your firmware via Wooveconnect. Note that if you have a 15B2 or 15SE revision unit with version 1.0, then the more recent 1.0 firmwares should already be MIDI IN capable for SysEx (on 1.0 too, hold 9/A1 while booting to put the MIDI port in MIDI IN mode). This allows you to update your 1.0 firmware Woovebox to 2.0 via any standard MIDI interface, rather than wireless MIDI.
Compatibility of your old 1.0 songs should be good overall, though fixed random seeds (7/hh/'SEEd' on a Song's GLob page) will yield different random value sequences in 2.0. Because there are some new subtleties in how fragments behaviors are reset, the "legacy version" parameter (8/Pc on a Song's GLob page) has been expanded to provide a 1.0 compatibility mode. Your "old" songs will automatically set this parameter as appropriate. Newly created songs will use "2.0" behavior.
Oscillator 3's signal is now also sent to the compressors/limiters, gating, side-chaining and ducking, these may need some tweaking depending on whether you were sending tracks with oscillator 3 to these.