Hello telboy1938
With your installation package you should have been given a "Technical Support" phone number. Usually the installation support is free (as they don't want to scare you off).
Give them a call, and if Sky are like my bunch, don't change anything, until, you and sky are both ready to complete the installtion. It is a leap-of-faith when you unplug and uninstall you old ISP.............Then the pressure is on to 'make' the new ISP work...............and you are never really 100% sure the new ISP S/W is going to run, on your PC
The Best Of British Luck.................and may the force be with you
Old Salt