Well Munir has a rel clause of 39,75mil€ right ?
Chelsea's budget is much bigger...so whats wrong with that ?!
Offer him a good contract(wage-6mil€/year+bonuses) he will accept instantly...
Spanish players always have a release clause. It's just what they do over there. Look at his contract page.
The thing is that Munir is quite loyal, but you're Chelsea, so he should be sufficiently impressed to sign with you.
But you need to offer him good wages and bonus after meeting the release fee.
just ask him on a loan untill the end of the season, he will come and in the end of the season, you'll be able to extend his loan how many times as you want.
sorry for any misspelled words, i'm portuguese (;