For the double-stop bend that starts in bar 89 bend the third and second strings a tone and a semitone respectively. This can be achieved by pushing the second string up and grabbing the third string on the way. With some practise the intonation can be mastered and plenty of finger vibrato will complete the effect. It’s worth spending some time on developing the repeating phrase that starts in bar 97. For the idea in bars 100 and 102 bend the first string up and catch the second string under the bending finger so it rings as well.