Husband is stopping sale of house right to dwell

[MilaRog]

My friend is unable to sell her house as her husband has what is apparently an occupancy clause/charge on the deeds of her house. He is refusing to sign papers to have this removed.
The house sale is due to be completed in the next 10 days.
What are her options?

The house is in her name solely as it belonged to her and her now deceased previous husband.
My friend's current husband left her 11 months ago and has his own property where he is on the voters register.

Generally my friend and her separated husband get on well but he is apparently wanting to sort out their financial matters before allowing the house to be sold.

Who does he respect most in this world? A friend, his dad, mum, who ever that person is, she needs to explain to them why it so important that they can complete this point in the process so they can move on to next stage positively. Then they can explain it to him and support him.

Getting him to cooperate is the fast way forward, so don't antagonise him, gentle persuation all the way.

I'm not up to date with current rules, but I think it used to be the case that a spouse had to be in actual occupation to be protected by an occupancy clause. A charge is a different matter - it would depend on its terms. Presumably she has a solicitor advising her if she is in the middle of a sale? Has she actually exchanged contracts?