Since im going to walk you through the whole process, it is best to learn this in new blender instead of an ancient version:
- delete all versions of blender you currently have;
- install blender 4.1 in the recommended location or on the d drive, nowhere else;
- in s4s settings change blender path to blender.exe in blender 4.1 installation folder;
- open the file with the base again, export a new blend,
do not use the old one;
- open the file with the ponytail and export the blend as well;
- open the blend file with the ponytail, select the hair, switch to Edit mode, select everything with A, Mesh - Merge - By distance;
- press Num5 to switch to orthographic view, then NUM3 for the side view;
- enable X-ray, click and drag to select as much of the ponytail as you can. Then press Select - Select linked to select the rest of it;
- Select - Invert to invert, then Delete - Faces to delete;
- in the outliner double-click on the meshgroup's name and change it to "ponytail";
- save this blend and close it;
- open the blend with the base shape, click at the top of the hair to find the base, hide other two meshgroups;
- switch to Edit mode, in UV editor enable Sync, click and drag to select those tiny uv islands. Select - Invert. In 3d view do Mesh - Merge - By distance again;
- File - Append - the blend with the ponytail - Object - the ponytail, append;
- delete bone_bone_shape.001 and rig.001;
- select the ponytail. Select all uvs, in the drop down choose Diffuse map;
- there is enough free space in the scalp area, you do not need to use accessory slots. Unless there is literally no other way, you must never shrink uvs. Smaller uvs = worse texture quality. The difference between the hair texture on the base and the hair texture on the ponytail will be very noticeable;
- select only uvs of the accessory and put them in the corner over there;
- select other uvs, press R 90 to rotate. Press G and put uvs above the hairline;
- It is possible to rebake texture after re-arranging uvs. Unfortunately, the author unwrapped the ponytail in a way that it wont work well, so you'll have to re-arrange textures manually. Select all uvs, UVs - Export UV layout;
- switch to Object mode. In 3d view select the ponytail. Press Shift D then Esc to duplicate it once. Duplicate again;
- unhide all hat chops. In this order: select ponytail,
Ctrl-select s4studio_mesh_1, in 3d view press Ctrl J to join. Do the same with ponytail.001 and s4studio_mesh_2, then with the remaining ones;
- save, close, import in s4s;
- open your image editor ( i'm using
photopea );
- open the texture of the base hair, then File - Open and place, choose the texture of the ponytail as well. Open and place the uv layout you exported previously;
- select the ponytail texture. Using box selection, select a chunk of texture where uvs used to be. Ctrl C to copy, Ctrl v to paste, select it. Edit - Transform - Rotate 90 clockwise, place behind ponytail's uvs;
- do the same with an accessory;
- hide the ponytail texture. Take an eraser and erase a portion that is too close to the hairline;
- hide the uv layout;
- if using photopea as well, File - Export as - png;
