The simplest answer besides diet is just to get some light exercise like walking around the neighborhood and maybe lift some light weights on days you don't walk.

The more you get the blood vessels and muscles expanding and contracting from pumping blood the more your pressure should naturally come down. I don't think it needs to be vigorous exercise but the more you can do the better.

Stiff rigid blood vessels from inactivity means your body has no natural pressure relief. It's just like any pipe system.