Share Based Payments

Hello Sir I have a doubt for replacing an equity-settled scheme with a cash-settled scheme. In the SBR Kaplan book the below was mentioned: An entity may modify the terms of an equity-settled share-based payment scheme so that it becomes classified as a cash-settled scheme. If this is the case, IFRS 2 requires the entity to: Derecognise the liability and recognise equity to the extent of the services rendered by the modification date. I don't understand the part where we derecognise the liability but we are changing the equity settled to cash settled scheme.