I concur with how to split them, but here's a good way to flavor up the lobster (I personally don't care for Florida/Caribbean spiny lobster especially when compared to Maine, florida slipper/dozers, Balmain Bugs, and Rock lobster as they're usually tougher with less flavor, so when I get them I like to spice them up).
After you've split them, coat them liberally in melted butter and this original Paul Prudhomme blackening mix (I cut the cayenne in third and only use a third of a teaspoon as the original is firey hot, even a third of a teaspoon is too hot for some).
http://www.saveur.com/article/Recipes/Blackened-Redfish
Place them flesh side down on flames as high as you can get and keep them there only 2-4 minutes (in exact time as there's no way to know how hot you get them) and then flip them for just a minute or two painting them with more melted butter. Do a touch test and when the flesh is firm and not gelatinous it is done. Do NOT overcook, these things turn mealy and/or rubbery really quick.
Take out the lobster meat and slice into large chunks. On the side burner heat up some flour tortillas in a little butter until a few brown marks appear and they crisp up a little. Then in the Center where you're going to fold it lay down a line of guacamole, add the blackened lobster, then add some thin radish slices for crunch, some tomatillo salsa, some Crema Mexicana (if you can't find it then use creme fraiche or sour cream Plus some shavings of a mild white cheese like Havarti or butterkase).
Trust me you will be the star of the party with Tribe's (as it's something I made up not a recipe I found) blackened lobster soft tacos. You can substitute shrimp (especially tougher/meatier varieties like rock or tiger) or crawfish for the lobster and cook it in the pan as well. I tend to do the panblackened shrimp or crawfish version of the tacos at least once a month. You can also make an amazing sushi roll by using the blackened lobster (or shrimp or crawfish), avocado slices, Mexican Crema and a splash of sriracha (plus the sushi rice and nori).