Some guidance on repitching, please

I moved my red ale (Edme kit + 3 lbs DME + Kent Golding hops) from primary to secondary after a quick (2 day) bubble fest and the complete reduction in the krausen. It's been in the secondary about a week, and the SG has been at 1.018 for a few days in a row.

Target FG is 1.010, so I am going to repitch with a packet of dry ale yeast my homebrew store sold me (Safale US-56, from Fermentis, if that makes any difference to readers).

Here's my question: are their any guidelines you can offer regarding repitching? For example, I was going to add the dry yeast to a cup of boiled water, cooled to 90-100 degrees, and just directly to the secondary, just as with initial fermentation. Is this fine?

Also, I believe one does NOT agitate / oxygenate the secondary, even when repitching. Is this accurate?

Any rules of thumb or other experience is most welcome.

Dry yeast will work even if it's just sprinkled on top.

Rehydrated yeast are re-awakened in a warm environment such as a cup of warm water. It does not have to be boiled water, but it will be safer for your beer at this point.

Have you tried just rousing the yeast that's in the secondary? Sometimes getting it back in suspension will re-initiate fermentation. That's an awfully fast primary fermentation. What temperature are you fermenting at?

Fermentation temperatures were between 72-77 degrees, probably around 74-75 most of the time. A little warm, but I've been told that this would not dramatically affect the final outcome. I was told that the fermentation would be fairly fast (by people here, and by my homebrew store).

His basic guidance was that if SG stagnated above 1.015, repitch.

How does one "rouse" in the secondary? I did stir it vigorously a few days ago to see if that would affect anything. If rousing = stirring, I did this, and nothing really changed.

So, any other guidance on repitching or rousing? Thanks, all.

One more piece of info...the temperature has been between 69-72 for the past 4 days (it was a little warmer, as noted, in the earlier days).

Yes, rousing/stirring essentially the same thing. If it were me I'd just sprinkle the yeast on top, but hb_99's method is assuredly safer.