Price of this service varies. Price ranging from 60-180 depending you seek service from which source. It's definitely replacing it, no way to repair it. Even you repair it, it could not last long; for a short period yes.

U gonna need to replace the flex underneath the home button.. Refer to post 4 on how the flex looks like.. U cant repair the used flex because the spring isnt that good anymore due to usage..

The repairman will dismantle ur iphone front assembly.. Seperating the digitizer and lcd.. Then only they gonna be able to change the flex.. Price as mentioned before its between rm60 to rm180 depending where u get it fixed.