For the installation of a pleated fabric one does not need expert knowledge. Pleats have been installed even by a lot of women as well as men who are not so technically interested. The easiest way and also the most gentle way for the window frame is a fitting via clamping support. (Klemmträger, Fensterrahmen)
Therefore, supports are screwed on top and bottom of the window frame, in order to later hang up the clamping feet with the clamping cord. (Spannfüße, Spannschnüre). In the beginning one should only tighten them so much as to allow an adjustment until the clamping cords run vertically from the support into the pleats. The fitting per clamping supports has the advantage that no drillings at the window frame or the wall have to be done, which can often be an issue between tenants and landlords in rented flats.
In case this is not a problem and you would like to drill you can also screw the pleats on the window frame with clamping cord angles or in the glass fillet. This looks more elegant. For glass areas, which cannot be opened – e.g. at window fronts in winter gardens or multi-partitioned casements – the fixture in the glass fillet is the only possibility to cover every individual glass area. However, the glass fillet should be either straight or only slightly sloping, otherwise not enough stability and tension can be achieved. Due to the fact that the pleated fabric is very close to the pane, an air-permeable fabric should be chosen in order to prevent humidity and heat accumulation between pane and pleats.
Normally, the clamping cords are delivered ready-for-assembly according to their specification. In case little corrective actions are necessary, due to too tight or loose cords, you have to consider the following:
The pleats should never be changed in unfolded condition, otherwise the clamping cords could be drawn into the pleated fabric when loosening the screw in the clamping feet, which would then demand reparation by an expert. Better unhinge the pleats on top, then loosen the screws, pull out or rope in the cord a bit, clamp again and check if the tension is enough for the functioning of the pleats. This could require several trials, but is also manageable by a layman.