->The original code will be like this:

<record id = "sale_order_personal_rule" model = "ir.rule">
<field name = "name"> Personal Orders </field>
<field ref = "model_sale_order" name = "model_id" />
<field name = "domain_force" > ['|', ('user_id', '=', user.id), ('user_id', '=', False)] </field>
<field name = "groups" eval = "[(4, ref ('sales_team.group_sale_salesman'))] "/>
</record>

->This is the original code, but before making any changes we have to make the noupdate as false. In order to do that we can use the function tag as:

<function name = "write" model = "ir.model.data">
<function name = "search" model = "ir.model.data">
<value eval = "[('module', '=', ' sale '), (' name ',' = ',' sale_order_personal_rule ')] "/>
</function>
<value eval =" {' noupdate ': False} "/>
</function>

->Now we can modify the Record rule as we want.

<record id = "sale.sale_order_personal_rule" model = "ir.rule">
<field name = "name"> Personal Orders </field>
<field ref = "sale.model_sale_order" name = "model_id" />
<field name = "domain_force">[(1,'=',1)]</field>
<field name = "groups" eval = "[(4, ref ('sales_team.group_sale_salesman'))]" />
</record>

-> <field name = "domain_force">[(1,'=',1)]</field> , This is a special rule, that unconditionally gives access to all records.

->Now make the noupdate as True again.:

<function name = "write" model = "ir.model.data">
<function name = "search" model = "ir.model.data">
<value eval = "[('module', '=', ' sale '), (' name ',' = ',' sale_order_personal_rule ')] "/>
</function>
<value eval =" {' noupdate ': True} "/>
</function>

->So now onwards on upgrade of the module the rule will get updated if we had modified the record rule.

->You have to do this with all the rules which you want to give access.