SIL OFL Fonts
There are other web fonts technologies, such as EOT (Embedded OpenType). Each of these modifies the font in some way, and so according to the SIL Open Font License (OFL) the font name must be changed. You are allowed to use these technologies to deliver fonts to web pages, but you must change the font names and follow all other OFL rules. We do not offer any support for these technologies. Note that although Google Web Fonts uses these techniques they have signed a special agreement with SIL that allows them to release modified fonts with the original names.
Hi David,
First, check whether we provide a WOFF version of the font you're interested in using: http://scripts.sil.org/SILFontList
If not, the OFL FAQ section 2.2 addresses conversion of OFL fonts to WOFF format: http://scripts.sil.org/cms/scripts/page.php?item_id=OFL-FAQ_web#1db14da7
Hope this helps!
Peter
For Modified Version you are required to change the name inside the font file itself (the names in the metadata fields of the font).
To make these changes you need a font editor like Glyphs or FontForge (there are command-line utilities but it's probably easier with a graphical editor).
Glyphs is proprietary, OSX-only but provides a trial version. FontForge is cross-platform libre software (open source) and can be downloaded at no charge: http://fontforge.org
Go to Element -> Font Info... -> TTF Names then right-click on the relevant entries to modify them.
See http://designwithfontforge.com/en-US/The_Final_Output_Generating_Font_Files.html for a screenshot.
BTW, beware of fontsquirrel optimizing away features that you actually want. Depending on the font it can be a good idea to see if the original author can help you with making a derivative webfont version.