In general, it's easy. But you need the right tools, enough time, and space. A torque wrench and specs are important.
The rears are very easy: undo the two bolts holding each damper in place, top and bottom. The swing-arm suspension then drops lower, enough to manoevre the spring out. Just avoid dropping the top bolt/socket into the chassis rail (but if you lose them, you can retrieve by taking out the rear seat to access a service hole). Reuse the rubbery spring 'platforms'.
Fronts are a bit more work. 'Crack loose' the top damper nut first, which will make it easier to remove once the strut is out. After releasing the main bolts holding the strut unit (3 at the top, 2 at the bottom), be careful that the bottom of the damper does not push hard onto the rubber CV joint boot; it can tear the boot. I jammed a thin piece of scrap wood between them for protection.
It can be difficult to manoevre the strut out. It is easier if you undo more and more parts, like the steering rod, and particularly if you release the lower wishbone (but should not be necessary to do this).
Undoing/tightening the top nut holding the top plate to the damper can be a little tricky. It's possible with the 'special tool'.
To line up the bolts when refitting the completed strut, I used my hydraulic jack to support the hub/disc brake from underneath.
Get hold of the workshop manual. It illustrates the steps nicely, and has all the bolt torque specs.