OK, I tried a flat head screwdriver last night, but tonight's new method is dental floss. Loop it around one or two turns at the end of the spring you are putting in last and feed the ends of the floss through the hole in the leg. Securely hold the other end of the spring in place around the servo arm piece. Then use the dental floss to pull the lower edge of the spring into place. The spring will bulge, as shown in the video, but keep holding that first end in, as it will want to pop out. Once it's over the lug, I place the leg on a spongy surface (mouse mat), spring bulge side down, and press firmly. All legs completed!