Check Mark Resize

So I use Visual Studio Blend for my excutor and stuff, then I added a check box and then I pressed edit template to get the XMAL code and then I resized everything I needed so everything way going greate, EXCEPT I realized I can't resize the check MARK no the check box but the check mark. So what should I do? I'm editing the template to do the XMAL code. So like what do I type and where do I type it in the XMAL code. Since it won't let me change the size or the check MARK.