Firstly, they need to get rid of their entire senior management and executive team; all of them, without exception - even if some are competent - to demonstrate a major change to any potential investors.
Secondly they need to abandon Sailfish as a distinct OS. They've proved wholly incapable of maintaining and upgrading it at any remotely reasonable cadence.
They should do as the KDE team have (and no doubt others will in future) and use Ubuntu Touch as a basis for their work.
It'd have way better performance and features,
less work for them, and it'd be able to tap into a platform and community which OEMs have already shown serious interest in.