Ok not sure what end caps you are using but if the wire just pushes in then you could use a paperclip that
is bigger then the wire to open the spring that holds the wire and remove the wire

If this dosnt work for you then cut the wire about 6" from the endcap and use wire caps or other method of slicing the wire just shrink tube or some other method of waterproofing it and it will be fine

Mainly just don't leave a piece of wire exposed where it could short or electrocute you

As for staggering the lights you would need to use separate ballast