Charge a LOT for admission, and include the ability to play with a bunch of the best toys. Then, if you buy a new toy, ~75% of the admission price goes toward the purchase price. I bet they'd make a killing.
Six Flags' and Disney gets away with charging absurd ticket prices since parents will pony up because their kids will manipulate them into it. Especially if "all the other kids" are going or there is a school field trip. Most parents these days are too busy and too soft to disappoint.
And then there's concessions (IKEA and Costco do it).
Shopping as entertainment adventure rather than pushing a shopping cart down aisles of loud marketing boxes floor-to-ceiling.
And, they need to work with apps and games publishers to have the next Cabbage Patch or Transformers not just in iPhone-like limited supply, but as a whole launch event.
But Toys R Us has the name brand recognition that this doesn't. If they just reframe the idea of going there from a place to shop to a place to play (and buy your favorite toys to play back home) then they'll get back all the sales that they've lost to online shopping.