No need for an IT tech, you can do this yourself! Not hard at all.
- If you want to connect all your devices to your Belkin wifi router make sure you know your wifi password.
- Next in the settings for your iPad go to wifi and next to Comcast press the little circle with i inside, than press "forget this network"
- than all you have to do is select your Belkin wifi router and fill in your password.
I am not sure if your old phone also was an iPhone, if so use the same steps as for your iPad. If not there should be something similar in the wifi settings to forget or delete the wifi network.
Hope this helps.