I saw the other bass tab for this and it wasn't quite right, so I thought I'd fix it.
The intro is like this:
G|-------------------|------------------|------------------|
D|-------------------|------------------|------------------|
A|-----------5----5--|------------------|-------------5---5|
E|---------7----7----|--0--00--00--00--0|0--00--00--7---7--|

G|------------------|
D|------------------|
A|-------------5---5|etc.
E|-0--00--00-7---7--|

So that's how is starts, and then you basically just repeat the main riff:
G|------------------|
D|------------------|
A|-------------5---5|
E|-0--00--00-7---7--|
for the rest of the song. You stop in the middle for I think 37 bars, and during that 
just does some random slides. And then for the guitar solo, just do:
G|------------------|
D|------------------|
A|------------------|
E|-0--0-------------|
You play that six times, and after the sixth time you go right back into the main riff.
Then there's another change towards the end. I'll put it with the vocals to make it easier:
            Way down in   side,..  woman..  you need, yeah
G|---------|----------|---------|--------|--------------------|----------|
D|---------|----------|---------|--------|--------------------|----------|
A|---------|----------|---------|--------|------------------7-|-0--------|
E|--0------|----------|---------|--------|--------------------|----------|

Love!------------------

G|--------|-----------|
D|--------|-----------|
A|--------|-----------|
E|--0-----|---(0)-----|

Then you go back into the main riff again, and while it's fading, Jimmy Paige changes it 
a little, and to match that with the bass play:
G|--------------------|----------------|
D|-------------------5|----------------|
A|---------------5----|----------------|
E|--0--00--00--7---7--|--0--00--00-----|
Like that.
And that's it. Please rate and enjoy!