95 civic sedan.

first, how can i safety remove an old car alarm without messing up the wires that need to be connected to the car. what happens if i cut a wire and it needs to be connected? i can take pics to show u guys what it looks like to me it looks like hell.
i don't want to pull a wire and then have something not turn on.

second, does anyone know of any one seat rear seat? or what can fit back there?
im bored and want to try something different. a 3 seater.

third, is my ******* horn, i found the horn and theres no plug connected to it. the relay works, where can i find the wires that can connect to the horn. where do they start? the alarm horn just had a black and red wire.
or should i just get an after market one and it'd be easier?