Hello Leanne and welcome to planDisney!
It's always such an added delight for me as the current UK Panelist, to be able to offer some magical advice to another Guest from across the pond who's planning to 
Return to the World of magic at Walt Disney World Resort!
I can absolutely relate to your great question because like you, I've spent many jolly Disney holidays with differing groups of both friends and family who've all been connected to 
My Disney Experience.  And if I left everyone on my list, it certainly could become rather confusing! 
With a little pixie dust and by following these easy steps, I'll try to guide you through those all important changes to your 
Friends & Family Planning on My Disney Experience -
- Firstly using a
 desk top computer, sign into your 
My Disney Experience account.
- Hover over the wording 
My Disney Experience which opens a drop down menu.
- In this drop down menu you'll want to click on 
My Friends & Family.  This opens the 
My Friends & Family List.  
- In the 
Friends & Family List go ahead and
 search for the Guest name you wish to remove.  Beside their name on the right hand side, click the wording 
Update which is highlighted in blue.  
- This opens up a new window where you'll see the option to 
Remove from This List again highlighted in blue, follow this link & click 
Remove to delete this connection. 
- Repeat steps for all the connections you wish to remove.
If for whatever reason you're still unable to edit your Friends & Family list, then I suggest speaking with a knowledgeable Cast Member who will be able to have a more in depth look at your My Disney Experience account by calling the 
free phone number for 
Technical & Website Support contained within this handy 
Walt Disney World Resort Contact Us link.
I hope I've fully answered your question today Leanne!  Please always feel free to pop back to 
planDisney with another enquiry about visiting Walt Disney World Resort.
Have a great Disney day ~ Jane