You need a spring compressor to get the old springs off - usually you can
get the struts back together without compressing the springs because they
are shorter.

Which Eibachs? The 'sportline' are very low, and ride like a truck. The
Pro-Kit are not as low, and ride much, much better (although still rougher
than stock). Both would appreciate new high-performance struts - but will
work for a while with the stock struts.

The best thing to do is get a Honda shop manual for your Civic and use those
instructions.....

Ned