How to migrate cakephp 2.6 models to cakephp 3.8?

I read the cakephp documentation but can’t find a way to migrate the models from my 2.6 Application to cakephp 3.8. I want to migrate my app, but the new model structure is completely diferent.
Example:
I have a model called Aluno that references a table alunos in my database with this content:

<?php

class Aluno extends AppModel{
        public $name = 'Alunos';
        public $order = 'Aluno.aluno ASC';
        public $validate = array(
    'aluno' => array(
        'required' => true
    )
);
        public $belongsTo = array(
	      'Cidade' => array(
	      	'className' => 'Cidade',
	         'foreignKey' => 'cidade_id',
	         'fields' => array('Cidade.id','nome','estado_id'),
	         'conditions' => array(),
	         'order' => array('Cidade.id' => 'ASC'),
	         'dependent' => true
	      ),
        'Bairro' => array(
	      	'className' => 'Bairro',
	         'foreignKey' => 'bairro_id',
	         'fields' => array('Bairro.id','Bairro.nomebairro'),
	         'conditions' => array(),
	         'order' => array('Bairro.id' => 'ASC'),
	         'dependent' => true
	      ),
        'Sexo' => array(
	      	'className' => 'Sexo',
	         'foreignKey' => 'sexo_id',
	         'fields' => array('Sexo.id','Sexo.sexo'),
	         'conditions' => array(),
	         'order' => array('Sexo.id' => 'ASC'),
	         'dependent' => true
	      ),
        'Naciopai' => array(
	      	'className' => 'Nacionalidade',
	         'foreignKey' => 'nacionalidade_id',
	         'fields' => array('Naciopai.id','Naciopai.nome'),
	         'conditions' => array(),
	         'order' => array('Naciopai.id' => 'ASC'),
	         'dependent' => true
	      ),
	      
        'Naciomae' => array(
	      	'className' => 'Nacionalidade',
	         'foreignKey' => 'nacionalidade2_id',
	         'fields' => array('Naciomae.id','nome'),
	         'conditions' => array(),
	         'order' => array('Naciomae.id' => 'ASC'),
	         'dependent' => true
	      ),
	      'Cor' => array(
	      	'className' => 'Cor',
	         'foreignKey' => 'cor_id',
	         'fields' => array('Cor.id','Cor.cor'),
	         'conditions' => array(),
	         'order' => array('Cor.cor' => 'ASC'),
	         'dependent' => true
	      ),
	      
	       'EscolaTransporte' => array(
	      	'className' => 'EscolaTransporte',
	         'foreignKey' => 'escola_transporte_id',
	         'fields' => array('EscolaTransporte.id','EscolaTransporte.transpescola'),
	         'conditions' => array(),
	         'order' => array('EscolaTransporte.transpescola' => 'ASC'),
	         'dependent' => true
	      ),
	      'User' => array(
	      	'className' => 'User',
	         'foreignKey' => 'User_id',
	         'fields' => array('User.id','User.nome', 'User.username'),
	         'conditions' => array(),
	         'order' => array('User.nome' => 'ASC'),
	         'dependent' => true)
	   
	      );
	       
}

?>

How can I migrate this to 3.8 model format?

P.S.- Sorry for my bad english…

See: https://book.cakephp.org/3.0/en/orm/associations.html

Migrating from Cake 2 to 3 esp. on database related code (tables) takes a lot of work. There’s no automated, easy solution.

There’s an upgrade tool that can do the easy things like rearrange file structure and add namespaces, but converting your validation rules, for example, is a fully manual process.