You need to change the port number in two file locations.
Firstly, in the Services.conf file located in C:\Users\<USER>\AppData\Local\Programs\Qlik\Sense
Third line down is the BrokerPort which will be set as 4848
Second location is the config.js file located in C:\Users\<USER>\AppData\Local\Programs\Qlik\Sense\HubService
(Right click and select edit)
Change the config.enginePort which is set as 4848 by default.
Save files and open Sense Desktop. You should now be able to access via the browser over the new port.