Some packs have a plastic cover like on a choclate box.
The dispensed drugs per the prescription* is usually attached to this.
The lid taped down to prevent accidental damage to the popable plastic layer covering the tablets.
Insert a blunt knife at the back fold to find the clear tape.
The popable plastic cover is stuck over the 'blister cup'
To open blister
Leave the tray on a counter
Gently press the plastic to pop it
Cover the opening with the dish lift and turn the package upside down and let the tablets fall into the dish
Or
Pick the individual tablets out and place in dish
The cover can be opened like a book but provided the tray is stored in a safe place may be easier to cut this off at the start of the week but this removes the prescription*
NB the packs should be delivered a few working days before needed and checked as mistakes do happen
_
Some things to think about with a dementia patient and care plan discussion
Most care companies will only allow "prompting"
Find out exactly what that means
How do staff deal with refusal or questions and dropped tablets
Will they only do a handover or place on a spoon and feed it if necessary
How is the carer recording they gave the tablets on care record "gave tablets" v "gave lunch blister"
the carer should check that the plastic layer was added and properly stuck down around the sides & corners 
As there will be multiple carers I would suggest getting 2 souffle / ramekins dishes each of different colours/shape
Have 2 different clearly marked storage areas for Mum and Dad and the dish is cleaned and stored with the tablets
If your parents are moving to prepacked are they able to identify their current tablets?
Tablets will end up on the floor.
Have the prescription* including pictures in the care plan and with the tablets
Have colour pictures back and front of the tablets for each blister
(If you are not sure of the meds do this in the pharmacy
Lay the prescription* on table
For each item place
flat tablet face up face down
tube ones with lettering roll up
Adjust the phone resolution until the markings are visible)
Send the pics to anyone who will be a carer contact
The pharmacy need to notify when there is a brand substitution
You need to update when this happens or there is a change to the prescription
Check the dispensed drugs against the original prescription given by the doctor and make sure you can identify individual tablets
Even though they should be checked tablets can be missed altogether or 2 in the same blister 1 day and none the next
Or the new prescription is sent after the tablet tray was made up by the pharmacist
If there are essential tablets can the pharmacy try to group these so that if missed they can be taken with a second blister
E.g. paracetamol is not in both blisters
The care company may have good suggestions too so ask them for advice on what works for each level of dementia as early introduction of a new routine may be better than trying to change a fixed expectation your parents may have