Tool is correct, maybe turn the camshaft further so that the lobe is 180° from the follower. In the case of the pictured shim all you need to do is get some long nosed pliers and pull it out from the side the photo was taken from. Sometimes the oil film will hold the shim to the bucket and if this happens you just use a small pick or screwdriver to gently lever it away, use the small cutout in the bucket to do this.