Raising cash by remortgaging is still a relatively chep way to borrow money. Secured and unsecured personal loans offer rates that rarely compete with a remortgage rate.
It is often advisable to contact your existing lender if looking to raise cash. They may be able to offer a favourable deal. Existing lenders will probably not be so positive if you have not been faultless in meeting your monthly payments.
Remortgaging to a new lender will mean a new application and meeting the underwriting requirements of the specific mortgage product you are applying to. You can choose a product by sifting through the lender websites, or by speaking with a mortgage broker.
A broker will be able to give you up to the minute information on the products available. They should also be able to tell you how much the mortgage will cost in fees, interest, and break this down over different time periods. This information will be important if you are looking to remortgage in the next few years.