youd have to scrap the neck, use the belt (or craft a new unity one) and then craft whatever secondary one
Well if you decide to re-install and craft a new normal legendary, make sure you take your current one (the cov leg) to the rune carver so he can trade the resources back to you. At least that won’t be a total waste, as frustrating as the situation is.
Just ran in to this issue and it’s a total joke that this even happens.