Can the hard drive on MacBook Pro (Retina, 13-inch, Mid 2014) be replaced to bigger size

I currently have a MacBook Pro (Retina, 13-inch, Mid 2014, 2.6 GHz Intel Core i5, 8 GB 1600 MHz DDR3).

The current internal drive is 128 GB SSD, but I need a bigger internal drive. I have contacted a few computer shops and half have said yes we can do it and half have said no. One said it can not be done and the others are telling you wrong.

Question is can the internal drive be replaced?

Yes, its possible. There is an entire guide for it as well. It's simply a matter of opening the laptop back panel, and swap the SSD. You would need the right screwdrivers for it though.

Also note that you don't necessarily need the expensive apple ones. It is possible to use a regular NVMe SSD that's quite cheaper with an adapter. Have a read at first post of this thread.

You might or might not have to tinker with deep sleep or hibernate settings if you face any issues when the laptop goes to sleep and unable to wake up. But I just swapped my SSD on a Late-2013 model and I didn't have to. Big Sur updates come with firmware that seems to have fixed those issue.