read my bold replies above
also, the heat sheild comes off first, so u can access all the 4 top nuts, then the 2 underneith are from under the car with a spanner (i dont think u can get a rachet on them) also, if ur jjr pipe is the same as mine, which i think it is, you wont be able to get the passenger side bolt back in, as the pipe warps over it, i wouldnt stress to much on it, the bottom and top bolt/nuts should stop any leakage