Using the kit glazing and fuselage profile as a guide, carve a male mould, or moulds, from balsa. Allow for the thickness of clear plastic sheet to be used when doing this, of which more later.
Once you are happy with the male mould, seal the grain of the balsa with a mix of clear gloss varnish and talcum powder, using enamel or polyurethane varnish, not acrylic. Let this harden totally, for a few days, then apply repeated coats of gloss varnish (again not acrylic), allowing each coat to thoroughly harden first, until a completely smooth, shiny surface is achieved. This is most important, as an imperfect surface will affect the surface of the clear sheet when moulding.
Now, take a sheet of stiff material, such as balsa sheet or thin ply, and, using the male mould, place this on the sheet, mark around its shape, and cut out this shape to form a female mould. Note that the shape and orientation of the required part will determine which elevation of the male mould will form the shape of the female mould.
Obtain some clear plastic sheet from a model supplies outlet of the desired thickness, probably around 10 to 20 thou for this scale, and at least A4 size or near equivalent. Do not use cheap, 'what you can find lying around' plastic, as the properties of this will be unknown, whereas the modelling clear sheet is designed for the purposes we are looking at.
Cut a piece of the clear plastic sheet which will cover the aperture of the female mould, allowing a generous border all around, and fasten this tightly and securely to the female mould, obviously centred over the aperture. I normally find that taping it tightly on all four sides works well.
Take the female mould, with the male mould immediately to hand, and hold it a few inches above a heat source - a gas hob on a cooker is ideal - with the clear sheet uppermost. Keep the female mould moving in a circle as you gently heat it and, as soon as it starts to go 'floppy', but before it totally sags or holes, plunge the male mould through the plastic and through the aperture, in one short, sharp, swift movement, but not so fast, or so far, that the male mould splits or ruptures the now heat-stretched plastic.
As soon as the plastic has cooled, probably a few seconds, carefully remove the male mould, then remove the moulded sheet from the female mould.
You should now have a moulded clear part, although this can often take more than one attempt.
Given that the part is as required, replace the male mould inside the moulded part, and, with a sharp scalpel blade, score around the edge - do not try to cut - until the part is freed from the remainder of the now deformed sheet.
The part can then be trimmed and cleaned up as required, and, if desired, framework can be added from strips of pre-painted tape. Fitting it is your problem!
Pics attached showing an example of this, when I moulded a canopy for my Mosquito conversion.