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As joint legal owner of the property, you are legally entitled to use reasonable force to gain access to the property. Therefore, you are perfectly entitled to get a blacksmith to assist and change the locks.
You are also of course also entitled to remain residing in the property until an agreement has been reached between the two of you as to what should happen to the property. The options are that the property be sold, or transferred into one of your names with the other receiving a cash settlement, representing their share in the property.
If the property were to be transferred into her sole name, this would entail her having to apply to your existing Mortgage Lender to have the mortgage transferred into her sole name, and if they agreed, you both would have to instruct your own Solicitor to deal with the paperwork and the payment due to you.
The Mortgage Lender would assess if she could afford to pay the Mortgage from her own finances, for this to be a viable option. If they do not agree, then the only option open to you would be for the property to be sold. If she did not agree to a Sale, you are entitled to issue Court proceedings to force a Sale, although this would be an expensive job and therefore your last resort.
I hope this assists and answers your question.