As we all know, ezreal is a long range high mobility champion.
so why not put him in the top lane? if you build him slightly tankier, he can be really annoying to the other team, especially since mystic shot procs on hit effects.

Essentially your job is to spam Q to proc the gauntlet + frozen mallet on hit effect to be annoying. Although this build will only land you between 200 and 230ad, you will still do lots of damage and because of your build, you will be slightly tanky and have CC abilities. This build favours sustained poke over time rather than all in engagements as AD ezreal has no burst.

attack damage marks
attack damage quints
Armour yellows
magic resist/cdr blues

CDR blues are nice because it allows you to spam that Q

Get your R whenever you can.
then Q
It is up to you whether you want to then max W or E
maxing W afterwards allows for more reliable damage, whereas maxing E allows for lower cooldown escape/mobility

Okay lets talk about items.
1.
Start with a dorans blade and as many health potions as you can buy.
This allows you in lane sustain, gives you some damage and health.

2.
On your first back, you want to get either vamp sceptor or boots. Early boots aren't bad, but i
suggest vamp sceptor.
3.
boots after vamp sceptor.
4.
Now build a sheen if winning lane, if not, glacial shroud.
5.
try to finish boots not too late into the game.
6.
finish your iceborn gauntlet
7.
Finish blade of the ruined king.
8.
Time for frozen mallet, same principle, winning lane, build attack damage item, losing lane, build health item.
winning lane = build last whisper now
losing lane = build visage now
This is of course assuming the entire game is laning phase. which never happens.
Judge for yourself whether you need more damage, or more survival

Feel free to change blade of the ruined king for a bloodthirster if you are looking for more damage and the enemy isn't stacking much health.
Banshees veil is also nice if you are being aimed and nuked/bursted
Also, if you are against an AP laner,get your sheen in lane for the damage, however do not finish it into gauntlet just yet, buy yourself some magic resist.

Pros:
High mobility
Long range
Functions as a second carry
Does not need to be babysat during lane phase.
Cons:
There are many more bruisers who have more CC and are more "useful" to their team
Can have an annoying in lane due to him being an AD carry.
If you fall behind early, well. goodluck have fun.
weak to people that have dashes and lockdowns.

Just auto attack and Q. not really difficult

As said before, spam that Q
position yourself so you can land your Q to proc the slows.
sit near the front line as you are an offtank of the team.

Try to get a tank jungler and/or tank support that has initiate.
because more than usual, the top laner has some sort of initiate, which Ezreal does not have.

Arcane shift (E) into the middle of the enemy team.
stand still. ALWAYS MOVE AROUND.