Once you receive LAA then you have 2 options to choose from, 1) Accept LAA and arrange to submit complete application 2) Decline LAA. At this stage you are not able to make any sort of changes in your EOI since if you sign to your MPNP online account you will ask to submit your application.
Please keep in mind few important things before you choose to decline:
1) The last draw of MPNP (EE) category was held on 9th July, 2018 so it means it is more than 3 months now since the last draw.
2) You are taking a bit of risk if you choose to decline (Not recommended, but you have the option to decline) since the next draw of EE category may/may not held during next few months.
3) If your points are more than 600 in EE category then it is somehow advisable to choose this option, since most of the draws during last 3 months has highest cut-off points.
4) Criteria of calculating points in EE for education is strict, since Educational Credential Assessment (ECA) is now compulsory to be submitted, however in normal PNP you submit your educational degrees without any ECA. (Sometime you loose points in this category because of difference of educational levels in different countries)
On the other hand, the positive side of EE category is its quick processing time of 6 months compare to around 15-19 months (This processing time consumed at Federal stage of application and does not include the time taken by Province for nomination).