Tips for Trimming blue spruce?

Yikes. Hope this site helps, but I think you’re going to have to be patient. Apparently they don’t like being told how to behave.

http://homeguides.sfgate.com/shape-blue-spruce-76229.html

Not too much at once...

https://www.hunker.com/12583835/the-best-time-to-trim-a-blue-spruce

Start trimming the ends about 1" twice a year until you get them back to the edge of your sidewalk. Then trim them just to keep them even with the edge of the concrete.

They want to be big trees - 40' diameter branch span at the bottom; they were planted too close to the sidewalk in the first place. If these are the so-called "dwarf" variety, they will have at least a 12-foot diameter branch base when mature.

Don't bother trimming them; you'll never be happy. Take them out and replant with something that will stay within bounds, planted an appropriate distance from the sidewalk for the mature size.

Also, Colorado blue spruce across the nation are dying of a needle drop disease; if yours don't show signs yet, they eventually will, and you will have to take them out anyway. Look around your town, and you will see a number of large blue spruce - dying or already dead.

if you try to dig them up, they will die. what we did was to trim up the bottom branches, so as not to lay on the ground. then we trimmed the branches back to look like a Christmas tree. every year we trim the outside and inside to get all the dried branches out of there. we've had our tree 30 years and it's doing great. we don't let it get higher than our gutters.