You have to have a deoxys in your party. Then go to Veilstone City. Go to the meteorites in the holes. Touch one of the meteorites. Press A and check your deoxys. If I'm right, your deoxys will be a different form. A meteorite has a different form, one will be special attack, attack, defense, or a speed form. I learned this by having my deoxys in my party and touching the meteorite.
They change deoxys form
In veilstone city at the east there will be four meteorits that each have the ability to change the form of deoxys that are: (attack form), (defense form), (speed form), (normal form).
use it to change deoxys's form
Currently there are no Braille caves you can interact with to change Deoxys' form. To get an Attack Form Deoxys you need to trade one from Pokemon FireRed. This is due to Deoxys' default form being different between the GBA Pokemon games. This mechanic was likely put in to encourage trading between the games. In every game since Pokemon Emerald there has been a way, usually a meteorite, that will let you change the form of your Deoxys.
go to Narcene City Museum and on the left there is a meteor press the A button on your DS it will change Deoxys form
Veilstone City.
To Change Deoxys's Form You Need To Go to The Southwest Part Of Route 3,with Deoxys In Your Party,Stand Near The Top-Left Meteorite To Change Its Form To Normal,Top-Right For Attack Form,Bottom-Left is Defense Form,And Bottom-Right For Speed Form.
There are meteors in between pewter city and mt.moon that can change deoxys form
oh nvm it does it randomly
if u are asking how to change its form then go to veilstone city and go to those rocks but u have to have a deoxys in the party
Go to Nacrene meuseum in Nacrene city. On the left, there is a meteor that will allow you to change Deoxy's form if you have him in your party.
Go to Pewter City and there are meteorites there. Check it and I think Deoxys will change form. (There are 4 rocks: for each of the 4 forms.)