File menu > Export > Partial > Select (select the families and family lines you wish to include) > OK (Remove the check mark from "LDS data", and any other info you wish to NOT share e.g. Contact information, Confidential data, Full information on living) > Export (select a name and location to save the file, and be SURE to remove "*" from the file name) > Export > OK
If you wish to review the gedcom before sending it (always a good idea), create a new PAF file called Temp.paf (File > New) and import the gedcom. (File > Import)
If the gedcom contains the desired information, send it to your friend as an email attachment. If not, you can always create a different gedcom. It only takes 5-10 minutes.
NOTE: Windows only allows 1 file to have any particular name and path. If you create a new PAF file with the same name as an existing file (and in the same folder), the new (empty) file will replace the other file. This can be disastrous if the file being replaced is your main genealogy database. So make sure that you name your temporary file something like Temp.paf