Hi
@Nellie to NGA
How tall is your plant? How long has it been planted? Skyrocket junipers reach a height of 15 to 20 feet but are very narrow plants (3ft average). From everything I was able to find about pruning skyrocket, nothing suggests cutting off the top. One link I found stated a gardener cut the top 5 feet off the homeowner's shrub and the info given said it would be stunted and may not recover .
If it is small enough, you might be able to move it rather than cut it.