I've accidently installed the wrong font as 'Helvetica'. I found a font called Helvetica online when I was looking at desktop customization, etc and I went and installed it. However, it's not actually Helvetica. I've now got a proper Helvetica font, but I can't seem to install it (it installs as Helvetica LT Std. Is there any way for me to delete 'Helvetica' and rename 'Helvetica LT Std' to 'Helvetica'?