replacing string in a file

[fusa]

I want to replace the following string:
mnt\I\F
with:
mnt\F\F

I know to use something like:
sed -i 's/I/F/g' filename

but don't understand how to process the \ characters, using:
sed -i 's/mnt\I\F/mnt\F\F/g' filename
isn't working.

I want to do something like:

find . -type f -exec sed -i 's/mnt\I\F/mnt\F\F/g' {} \;

[cfajohnson]

Escape the backslashes:

find . -type f -exec sed -i 's/mnt\\I\\F/mnt\\F\\F/g' {} +

[fusa]

Thanks for your help. Thought for sure I tried that, but guess I didn't since it worked