The most important thing is that you ensure you have a copy of your line. This is the bit that gets you your sky channels.
You say old version so cannot be 100% sure your settings will work with the latest version of WooshBuild, but again, as long as you have a copy of your line somewhere safe away from your box things will be ok.
First thing to do is backup your settings: Blue button -> Backup settings. This gets saved to your USB Device in the box
Then, follow the instructions for flashing WooshBuild using the download you have. These are in the H2S section of the forum. When BaseBuild asks if you want to delete existing data from your USB SAY NO. This will then keep all of your recordings and you settings backup.
Once WooshBuild is fully flashed you can either import your line using thr USB cam importer if you are not bothered about your old settings and timers, or you can use WB Config (in plugins) to restore your settings backup.
1. Ensure you have a copy of your line safe somewhere
2. Backup your settings
3 Follow Wooshbuild v5 setup instructions
Good luck.