Two possibilities are illustrated on mapleshaderecords.com
First choice is to plug your fixed power cord into the top of the line Mapleshade powerstrip, and you will think you upgraded your fixed power cord. At least, that's what I found to my surprise, with my venerable fixed cord components, such as Cary SLA-70Sig amp.
Second choice, is to purchase top of the line fixed power cord upgrade kit from Mapleshade, where you clip off most of the original fixed power cord, using the remaining power cord pigtail as the start of your new power cord upgrade which clamps onto the old remaining pigtail, according to Mapleshade.
I simply used their powerstrip to get better transient speed, clarity, and increase in dynamics, rather than do power cord surgery on my amp.
Mapleshade is very responsive to email questions, so don't hesitate to check with the manufacturer.