Not easy to to do.
You need a totally re-designed head with an injector and a fuel puddle pocket built into the head and pistons + someway to mechanically boost the pressure up to around 2,000 psi or higher.
GM and Ford are using a mechanical pump based loosely off the old distributor drive idea to boost the pressure.
There's no electrical pump available yet that'll boost the pressures needed for directly injecting the fuel into the cylinder.
I think the post above is mistakenly thinking port injection is the same as direct injection,way differant.
You need fuel pressures that overcome cylinder pressures in direct injection,so you're looking at 2000 psi or higher,not 50 psi like a port injection system can get away with
