sure, use a hammer and smash out the old one and then use the hammer to smash in the new one..... it wont be useful, however
or as other stated unbolt the u-bracket from behind, disconnect the 4 wires from behind the dash, pull gauge out the front, install new tach and re-connect
however, need to ask, why are you changing the tach
I don't know how your dash is put together. I helped my pal pull his gas gauge to trouble shoot. His '94 Rinker's gauge panel pulled from the dash w/a few screws and nuts behind. Then the whole assy. could be pulled far enough rearward to access the individual gauges. Gauge grounds are top on the usual suspects list. If all connections are tight and clean, another sage on this forum can tell you how to start checking downstream.