Left of IRON in UG

http://www.cadfamily.com/HTML/Article/Left%20of%20IRON%20in%20UG_443.htm
Right-click over the name of Front-cover in the Assembly Navigator, then choose Display Parent, and then choose Third as shown in Figure 1.

2. Right-click over the name of Fourth in the Assembly Navigator, then choose Make Display Part as shown in Figure 2

3. Right-click over the name of Fourth in the Assembly Navigator, then choose WAVE, and then choose Create New Level as shown in Figure 3. Then click the icon, then input “Left” as the name, and then click icon, and then click icon.

4. Right-click over the name of Left in the Assembly Navigator, then choose Make Display Part as shown in Figure 4

5. Click icon, then select the green block as the target body to trim, and then press the mouse middle key in the blank areas, then select the yellow face as the tool face as shown in Figure 5, and then click icon.

6. Click icon, then select the green block as the target body to trim, and then press the mouse middle key in the blank areas, then select the yellow plane as the tool face as shown in Figure 6, and then click icon.

7. Click icon, then select the yellow body as shown in Figure 7, then click icon, and then click icon.