firefox – Is it possible to change hyperlink into button with same href and name inside?

So i have hyperlink at a webpage that is:

<a href="123.com" onclik="this.href+='&amp;sub=442028';" name="1909e63d" class="cs"><b>456</b></a>

And i want it to be a button instead of hyperlink.

Like:

<input type="button" class="butt1" name="but" value="456" onclick="123.com'">

But since i have zero expirience with tampermonkey or greasemonkey i have zero idea where to start from. Note that href is dynamically changes.