Similar procedure for the armour of the leg, select the faces in red, Detach to a Clone and apply Push.
Adjust the vertexes like above in the front views, with to obtain these dimensions.
Extrude the faces as above each time with Bevel.
Extrude an edge then back for the interior.
Apply Meshsmooth, improve the positions of the vertexes of the low poly mesh if necessary until you have a regular form from every angle.
Crease Values to accentuate the edges with Meshsmooth.
The armour of the finished leg.
For this small part of armour to the top of the legging, start from a primitive Tube with 7 dimensions and adjust as above.
Finish the adjustment of the vertexes so it ties in with the legging.
For the armour of the thigh, same procedure as before.
Simplify the geometry by welding the vertexes marked in red (Weld Target).
Start to adjust the armour like opposite so the faces have these dimensions.