How do I change the Top-Level Category Text to Bold?

The images I have uploaded are from my previous website (4WD-Nation) which no longer exists, yet the Top-Level Category Text was changed to Bold.  Both 4WD NATION and VENDORS were changed to bold, that is what I would like to do to the NTS KBee that I have from you.

I no longer have the code for that old website.

I would like to make the Top-Level Category Text 'Bold'.  How do I do that? 

Thank You and Respectfully,

Tim