WilliamJ,
To install any plugins in MyEclipse 2015, you need to install either from Eclipse Marketplace (Help > Install from catalog) or using update site (Help > Install from site).
If you are behind a firewall / proxy, you need to configure the firewall/proxy settings here : Window > Preferences > General > Network Connections.
Follow these steps to install SVN using Eclipse Marketplace :
Navigate to Help (MyEclipse menu) > Install from catalog > Select ‘Eclipse market place’ instead of ‘MyEclipse secure marketplace’ > Search for ‘subclipse’ plugin > Click on install and follow the wizard to install the Subclipse plugin.
Alternatively, you can follow these steps to install SVN using update site :
Navigate to Help (MyEclipse menu) > Install from site > Click Add > Enter a name and add this URL – http://subclipse.tigris.org/update_1.10.x in the Location field and click OK > On clicking ok subclipse related components will be listed below, select the components needed and click next and follow the wizard to install the plugin.
When I try that it wants me to add a user id and password to the network set up but I cannot find where that can be done. When I click on the proxy rows in the table I cannot edit or add anything.
If you are still facing issues, Can you please attach the screenshots to help us get a visual of the issues you are seeing ?
Let us know how it works for you.