sinks\doors

by art
(mag. california)

two questions. i have a kitchen sink i want to change from a 33x19 to a 33 x21 is it possible to do so w\o weakening the counter top. also if the holes are not centered how difficult is it to change the pipes.

second question: is it possible to change the back door to a heavier security door or just a security door. thanks, art