Someone added incorrect data to my page, now I can't change it.

The most "right" thing would be to try and split the other person's information off to as that name constant (the ID with "nm") really refers to you (although in some ways that might be seen as being a little over literal and IDs change quite a bit thanks to splits and merges), but that is difficult to do with the other person's biographical information.

The "easiest" thing is to split your credits off to Ricardo Estrada (II) and perhaps beef up the bio so it'd be difficult to merge it back together.

However, I'd wait and see what staff say - they might be able to do the "right" split for you.

The thing is, how is the dispute to separate the two identities? Who gets to be Ricardo Estrada (I) and who Ricardo Estrada (II). The one who created the profile page first? The one who added the date and place of birth? Or the one with the most credits?

While Emperor is correct that making yourself Ricardo Estrada (II), IMDb policy has always been that Roman numerals should be assigned in the order in which the data was added to the database. I think it is important to maintain this policy in order to prevent people deliberately hijacking existing pages in order to be listed as (I).

This is not too hard to do, but will need to be done in two stages. You don't specify which credit is yours, but since each section contains only one Title, you can definitely use the Name Split option (second line on the main Update page)

Simply select I don't know [Estrado, Ricardo (II)] from the dropdown box for every department except yours. Do not check the boxes beside Update existing credits with 'as' - it doesn't apply in this case.
Enter the explanation : that you are the person for whom the page was created and that these later additions are for a second person with the same name.
Once you have clicked Check these updates, the form should turn green and you can Submit these updates

At this point you will need to wait until the new page is up and at least one credit has shown on it.

At that point, you need to do the second update. Choose to update each section that contains information that belongs the other person (e.g. Nicknames, Birth Date).

For each item that belongs to him, select Change in the Action field to the left of that item.
Check the box beside Show name? at the lower right corner of each form.
Check these updates.

The forms will now have another column, containing your name (probably Estrado, Ricardo (I) by this time). You need to change this name to match the name on the new page (i.e. Estrado, Ricardo (II)).
You should check the box beside provide an explanation to assist in processing this change for those items that don't already require the explanation.
Click Re-check these updates

Enter the explanation for each item: that you split the credits off in a previous update and are now moving the data belonging to that person to the new Name.

Note that the Note of Birth explanation needs to begin with a URL, but that can be any URL -- I would suggest a link to this thread and add a phrase like 'as described in this thread' to the explanation recommended above.
Click Re-check these updates

You should now be able to Submit these updates.

The reason this needs to be done in two stages is that, while it is possible to move Personal Data to a different existing Name, only a Credit can cause a New Name to be created. For this reason there is no option to 'create a new name' in the list of possible matching names, and you need to wait until the page actually shows up on the site to do the move.

I do hope the OP thanks DavidAH for such a great and detailed answer!!

Sorry, couldn't resist (tho hope they do, manners cost nothing!!....)

David :o)