Using nightly build feed

1. Add https://www.myget.org/F/perspex-nightly/api/v2/Packages to your package sources

2. Update your package using Perspex feed

If you experience some problems try to switch nuget to v2 feed - http://www.nuget.org/api/v2/

If you still can't update to nightly version try to uninstall Perspex package and install it again.