Can you get an right angle drill adapter in there?
Got mine at Sears with some stubby bits.
I had to do this when I changed my timing belt as a bolt snapped.
That is about 4 inches of area to work with and I got it done.
Go slow and keep it lubed and it will work.
Re-tapped it and you are good to go.
Patience my friend, patience.
2001 Mazda Millenia 2.5L Champagne Silver Mica 190,000 miles
2002 BMW 530iA Sterling/black 95,000 miles
2006 Volvo XC70 Blue 136,000 miles
2001 Mazda Millenia 2.5L Brilliant Black 213,000 miles - SOLD
1993 Mazda 626 2.5L ATX 235,000 miles - SOLD